Temporal Distribution Patterns Research Articles

An efficient model for solar radiation induced top displacement of steel-concrete composite bridge towers

The temperature effect caused by solar radiation significantly influences the stress state of bridges. Especially for ultra-high bridge towers, considerable deformation induced by solar radiation affects the safety of the structures. This research is conducted to evaluate the temperature deformation of a steel–concrete composite bridge tower where a sliding saddle is adopted. First, the temperature distribution pattern of the structure is analyzed. Second, based on the temperature distribution, an efficient model which can be applied to the long-term calculation is established, aiming at directly calculating the deformation results. Then, an outdoor experiment study is carried out to verify the temperature distribution and the results of sectional curvature. Finally, the efficient model is applied to calculate the annual bidirectional deformation. This method realizes the long-term temperature effect evaluation of the structure before construction, and the results can be referred to as guidance for the analysis of related types of structures.

Physical Simulation Test of Underground Coal Gasification Cavity Evolution in the Horizontal Segment of U-Shaped Well

A key point in the underground coal gasification process is the cavity evolution in the horizontal segment. The morphological evolution law of the gasification cavity has not been clarified, which is the bottleneck restricting the analysis of its controllability. In this paper, a physical simulation system for cavity generation was developed, and the cavity evolution in a targeted coal seam with overburden pressure was duplicated in the laboratory. A set of temperature field synchronous monitoring devices was developed to realize temperature sampling within a cavity and the surrounding rock. By analyzing the relationship between the overall temperature distribution pattern and the gasification agent injection condition, the morphological propagation law of the cavity is verified to be water drop-shaped, and influencing factors including the injection flow rate and the gasification agent component ratio are investigated. The axial length and volume of the cavity increase with an increasing injection flow rate. Higher oxygen content results in increased size in all dimensions. The research results provide theoretical support and reference for applying controlled cavity formation in the horizontal segment of U-shaped wells.

Spatiotemporal Distribution Patterns of the Sea Cucumber Holothuria arguinensis on a Rocky-Reef Coast (Northeast Atlantic)

The demand for sea cucumbers from the NE-Atlantic is increasing as a consequence of the depletion of stocks that historically supplied Asian markets. Some species from the NE-Atlantic are already showing overfishing signs due to either inefficient policies or their total absence, and they do not offer any margins of sustainability to sea cucumber fisheries. The current lack of knowledge of biological and ecological traits has led to ineffective protection of those species. Holothuria arguinensis is a good example of a temperate sea cucumber species suffering from the effects of unregulated and illegal harvest. This study aims to determine the temporal and spatial distribution patterns of H. arguinensis, assessing density and size-class structure in a NE-Atlantic population, in SW Portugal, as a function of environmental conditions. Sampling was done every 1.5 months at 6 stations defined according to habitat heterogeneity, following the coastline from the mouth of the Sado estuary to marine coastal areas. At each station, there were two habitats (rocky substrate and sandy areas) sampled through SCUBA diving along 30-m random transects, each with three replicates. Individuals were counted and measured (total length) and individual behavioural parameters, such as sheltering and settlement surface, were recorded. Water column parameters, sediment composition, and substrate cover were also recorded. Generalised Linear Models were fit to the data, modelling density and size distribution of the species with respect to environmental conditions. The results indicate that the distribution of H. arguinensis was mainly determined by its ability to deal with physical environmental stressors (current), rather than the chemical properties of the water column or sediment composition. The hydrodynamic features of the region exert the greatest impact on this species’ distribution and help shape habitat usage by different size class groups.

Evaluation of NEX-GDDP-CMIP6 in simulation performance and drought capture utility over China – based on DISO

Abstract Global climate models (GCMs) are the state-of-the-art tool for understanding climate change and predicting future. However, little research has been reported on the latest NEX-GDDP-CMIP6 product in China. The purpose of this study was to evaluate the simulated performance and drought capture utility of the NEX-GDDP-CMIP6 over China. First, the simulation skills of the 16 GCMs in NEX-GDDP-CMIP6 was evaluated by the 'DISO', a big data evaluation method. Second, the DISO framework for drought identification was constructed by coupling the Correlation Coefficient (CC), False Alarm Rate (FAR) and Probability of Detection (POD). Then, it was combined with SPI and SPEI to evaluate the drought detection capability of NEX-GDPD-CMIP6. The result shows that: (1) NEX-GDPD-CMIP6 can reproduce the spatial distribution pattern of historical precipitation and temperature, which performs well in simulating warming trend but fails to capture precipitation's fluctuation characteristics. (2) The best performing model in precipitation is ACCESS-CM2 (DISO 1.630) and in temperature is CESM2 (DISO 3.246). (3) The 16MME performs better than the best single model, indicating that multi-model ensemble can effectively reduce the uncertainty inherent in models. (4) The SPEI calculated by 16MME identifying drought well in arid, while SPI is recommended for other climate classifications of China.

Sperm whale distribution and seasonal density in the Faroe Shetland Channel

Results from previous surveys suggest that an area of the northeast Atlantic, the Faroe Shetland Channel, is important for cetaceans. This study utilised passive acoustic survey techniques to evaluate the density of sperm whales in the Channel. Two-week surveys were carried out during oceanographic cruises in May and October 2001, and May 2002. A two hydrophone array was towed behind the vessel throughout the majority of the survey routes and was monitored by a two-person team and by software designed to automatically detect and measure bearings to whales. Distances of individual sperm whales from the trackline were determined using target motion analysis. Standard line transect techniques were applied to calculate the density of whales during surveys. The effects of sea conditions and survey vessel on the ability to detect whales were tested; the encounter rate and effective stripwidth (esw) were estimated independently for each sea state and for each of the vessels. A total of 79 individual whales were detected, and their distances from the trackline were calculated. As a probable result of insufficient sample size and a small effects size, neither the esw nor the encounter rates varied significantly with sea state or between the two survey vessels. The density of sperm whales during each of the surveys was estimated to be 2.05, 0.52 and 1.75 whales per 1,000km2 for the May 2001, October 2001 and May 2002 surveys respectively. Sperm whales were distributed across the majority of the Faroe Shetland Channel. This study has provided the basis for meaningful hypothesis generation in future studies and to gain a better understanding of the factors underlying the spatial and temporal distribution patterns of sperm whales in this area; data on oceanographic, biological and anthropogenic determinants should now be examined.

Comprehensive Thermodynamic Analysis of He–Xe in Microchannels with Different Structures

He–Xe, with a 40 g/mol molar mass, is considered one of the most promising working media in a space-confined Brayton cycle. The thermodynamic performance of He–Xe in different configuration channels is investigated in this paper to provide a basis for the optimal design of printed circuit board plate heat exchanger (PCHE). In this paper, the factors affecting the temperature distribution of the He–Xe flow field are analyzed based on the flow heat transfer mechanism. It is found that the flow patterns in the logarithmic and outer zones determine the temperature distribution pattern of the flow field. A series of numerical simulations verify the above conclusions, and it is found that reasonable channel structure and operating conditions can significantly improve the thermodynamic performance of the He–Xe flow. Based on the above findings, the Zig channel is optimized, obtaining Sine and Serpentine channels with different structural characteristics. Comprehensive thermodynamic comparisons of the helium–xenon flow domains inside channels are performed, and the Serpentine channel with a shape factor of tan 52.5° is found with the best performance. This work aims to improve the understanding of the thermodynamic performance of He–Xe in microchannels and provide theoretical support for further optimization of PCHE employing He–Xe.

Spatiotemporal characteristics of high winds in Jilin Province during 1982–2021

AbstractHigh winds are a type of catastrophic weather characterized by wind speeds over 10.8 m·s−1, occurring in all seasons, and have become more frequent, impacting crop growth, agricultural production and quality of life. It is crucial to understand the spatial and temporal distribution patterns of high winds, as well as their speed and other characteristics, for logical planning of agricultural production and the creation of disaster resilience measures. This study applied the climate tendency, accumulative anomalies, theory of run, Mann–Kendall trend and Theil–Sen median to analyse the spatial and temporal distribution characteristics of the average wind speed and high wind days in Jilin Province, the probability of occurrence of high winds of various magnitudes in different eras, and the gale concentration degree (GCD) throughout Jilin Province for a total of 40 years from 1982 to 2021. The average wind speed and number of high wind days in Jilin Province have decreased over the past 40 years, and this trend has slowed over time. The average GCD in Jilin Province has shown an increasing trend over the last 40 years, with the average GCD being highest in Liouhe and lowest in Linjiang. In general, level six high winds were the main wind hazard level in Jilin Province, with the highest frequency occurring in different seasons and decades. In addition, the occurrence of high wind days is affected by global climate change and different underlying surfaces, which leads to maize and yield reduction. Research on the spatiotemporal distribution of high winds can provide important suggestions for the prevention and management of high wind disasters.

Numerical Investigation on Heat Flux Variation in Fuel Bundle Over Fully Voided Concentric Channel of IPHWR Under Severe Accidental Scenario

Abstract A steady-state thermal analysis is performed on a fully voided channel of an Indian pressurized heavy water reactor (IPHWR) by providing variable heat flux inputs of 800 W/m2, 1500 W/m2, 2500 W/m2, 3500 W/m2, and 4500 W/m2 for evaluating the numerical results of temperature distributions in pressure tube (PT) and calandria tube (CT) at concentric scenarios using a numerical approach. The top to bottom temperature difference of PT and CT is found to be 0.57% and 3.31%, respectively, for 800 W/m2 input heat flux, and this variation decreases to 0.015% and 0.05%, respectively, for 4500 W/m2 input heat flux, thus pointing out that increasing the heat flux leads to the decreased top to bottom temperature difference. Also, the temperature distribution pattern is found to be similar for all the input heat fluxes, and for a particular heat flux, the change in circumferential temperature is found to be negligible. The boiling phenomenon starts at 2500 W/m2, and the volume fraction of moderator vapor increases as the heat flux is increased, the average density of moderators inside the enclosure decreases, and continuous variation in film thickness is also observed with respect to time for a particular heat flux value. The results also showed that the moderator acted as an effective heat sink for higher heat input rates.

A Spatio-temporal Bayesian model to estimate risk and influencing factors related to tuberculosis in Chongqing, China, 2014–2020

BackgroundTuberculosis (TB) is a serious infectious disease that is one of the leading causes of death worldwide. This study aimed to investigate the spatial and temporal distribution patterns and potential influencing factors of TB incidence risk, and to provide a scientific basis for the prevention and control of TB.MethodsWe collected reported cases of TB in 38 districts and counties in Chongqing from 2014 to 2020 and data on environment, population characteristics and economic factors during the same period. By constructing a Bayesian spatio-temporal model, we explored the spatio-temporal distribution pattern of TB incidence risk and potential influencing factors, identified key areas and key populations affected by TB, compared the spatio-temporal distribution characteristics of TB in populations with different characteristics, and explored the differences in the influence of various social and environmental factors.ResultsThe high-risk areas for TB incidence in Chongqing from 2014 to 2020 were mainly concentrated in southeastern and northeastern regions of Chongqing, and the overall relative risk (RR) of TB showed a decreasing trend during the study period, while RR of TB in main urban area and southeast of Chongqing showed an increasing trend. The RR of TB was relatively high in the main urban area for the female population and the population aged 0–29 years, and the RR of TB for the population aged 30–44 years in the main urban area and the population aged 60 years or older in southeast of Chongqing had an increasing trend, respectively. For each 1 μg/m3 increase in SO2 and 1% increase in the number of low-income per 1000 non-agricultural households (LINA per 1000 persons), the RR of TB increased by 0.35% (95% CI: 0.08–0.61%) and 0.07% (95% CI: 0.05–0.10%), respectively. And LINA per 1000 persons had the greatest impact on the female population and the over 60 years old age group. Although each 1% increase in urbanization rate (UR) was associated with 0.15% (95% CI: 0.11–0.17%) reduction in the RR of TB in the whole population, the RR increased by 0.18% (95% CI: 0.16–0.21%) in the female population and 0.37% (95% CI: 0.34–0.45%) in the 0–29 age group.ConclusionThis study showed that high-risk areas for TB were concentrated in the southeastern and northeastern regions of Chongqing, and that the elderly population was a key population for TB incidence. There were spatial and temporal differences in the incidence of TB in populations with different characteristics, and various socio-environmental factors had different effects on different populations. Local governments should focus on areas and populations at high risk of TB and develop targeted prevention interventions based on the characteristics of different populations.

Spatio-temporal variability of available sulphur and micronutrients (Zn, Fe, Cu, Mn, B and Mo) in soils of a hilly region of northern India

Knowledge about spatio-temporal variabilities of plant available (hereafter called available) nutrients in soils is important for undertaking revised and efficient site-specific soil nutrient management practices in order to achieve higher crop production and nutrient use efficiency in different parts of the world. Despite emerging deficiencies of available sulphur (AS) and micronutrients in various soil-crop situations, the information pertaining to temporal changes in spatial variability of AS and available micronutrients in soils of different parts of the world is limited due to scarce studies in the said area. The present study was carried out to assess and compare the status and spatial as well as temporal distribution pattern of AS, available micronutrients, and some selected soil properties [soil pH, electrical conductivity (EC), and soil organic carbon (SOC)] in cultivated soils of a hilly region of India, in 6 years (2015–2021). We also visualized correlations among soil properties, AS, and available micronutrients, and studied spatial structures of the soil parameters. We collected altogether 2, 871 (1, 127 in 2015 and 1, 774 in 2021) georeferenced representative topsoil (0–15 cm depth) samples from cultivated areas of Uttarakhand state of India and analysed. Soil properties, AS and available micronutrients exhibited moderate variability with coefficient of variation (CV) values ranging from 10 to 100%. The mean values of AS and available micronutrients in 2015 and 2021 differed significantly, as revealed by t-test. The mean concentrations of AS (13.2 mg kg−1), available iron (AFe) (36.5 mg kg−1), available boron (AB) (0.92 mg kg−1) and available molybdenum (AMo) (0.40 mg kg−1) in 2021 were significantly lower than the concentrations of AS (44.7 mg kg−1), AFe (42.8 mg kg−1), AB (1.46 mg kg−1), and Amo (0.94 mg kg−1) in 2015. The AS concentration was positively and significantly correlated (r = 0.064 p < 0.05 in 2015, r = 0.261 p < 0.01 in 2021) with soil pH and negatively and significantly correlated (r = −0.082 p < 0.01 in 2015, r = −0.125 p < 0.01 in 2021) with SOC in both the years. There were positive and significant correlations of SOC with available zinc (AZn) (r = 0.111 p < 0.01), available copper (ACu) (r = 0.062 p < 0.05) and AB (r = 0.159 p < 0.01) in 2015 and with AZn (r = 0.101 p < 0.01), AFe (r = 0.187 p < 0.01), ACu (r = 0.164 p < 0.01), available manganese (AMn) (r = 0.169 p < 0.01) and AMo (r = 0.266 p < 0.01) in 2021. The exponential model was found to be best fitted for all of soil parameters with lower MSE values (−0.007 to 0.006 in 2015 and −0.010 to 0.012 in 2021) in both the years of estimation. The nugget/sill ratios (varied from 0.32 to 0.74 in 2015 and from 0.29 to 0.57 in 2021) indicated the moderate spatial dependence for all the soil parameters except AFe (nugget/sill ratio 0.14, strong spatial dependence) in 2015 and EC (nugget/sill ratio 0.24, strong spatial dependence) in 2021.There were varied distribution patterns of soil properties, AS and available micronutrients in the study area for both the years of estimation. The distribution patterns of AS, AB and AMo changed to a greater extent over the period of time. Thus, the study highlighted the change in spatial variability of AS and available micronutrients in the study area over a period of 6 years.

KARAKTERISTIK PENGERINGAN SAGU MENGGUNAKAN ALAT PENGERING TENAGA SURYA TIPE RAK1)

ABSTRACT&#x0D; &#x0D; This study aims to test the performance of a solar dryer for drying sago. Performance tests include: temperature distribution pattern, relative humidity of the air in the drying chamber, changes in moisture content, drying time, and drying rate. The benefits of this research are expected to use a rack-type solar dryer to shorten the drying time and also this tool can provide an overview of the use of solar energy in the process of drying sago and drying other crops. During the drying process there has been a temperature difference between the bottom shelf, middle shelf, top shelf, chimney and ambient air temperature. The average relative humidity of the ambient air on the first day is 63.75% with a maximum condition of 67% and the lowest air relative humidity condition is 60% and the average relative humidity of the air inside the device on the first day is 34.62% with a maximum condition of 37% and the lowest air relative humidity condition is 33%. The average relative humidity of the ambient air on the second day is 65.66% with a maximum condition of 69% and the lowest air relative humidity condition of 62% and the average relative humidity of the air insi de the device is 35.83% with a maximum condition of 38% and the lowest air relative humidity condition is 33%. The mathematical model of the relationship between water content and time on the bottom shelf is y = 0.6305e- 0.127x with R² = 0.972 on the middle shelf y = 0.6149e-0.118x with R² = 0.9875 on the top shelf y = 0.6434e-0.11x with R² = 0.9649. The drying rate on each shelf is different and changes occur every time because it depends on the mass of the material. The average drying rate on the lower shelf is 3.40%, the middle shelf is 3.31%, and the upper shelf is 3.21%. To reach a moisture content of 11-14% requires a total of 13 hours for 2 days.&#x0D; &#x0D; &#x0D; Keywoards : sago drying, rack tipe solar dryer

Alp-valley and elevation effects on the reference evapotranspiration and the dominant climate controls in Red River Basin, China: Insights from geographical differentiation

Complicated topography can drastically affect the geographical distribution of evaporation, runoff production, water cycle, and water security guarantee. However, whether the elevation and Alp-valley have differentiated effects on basin evaporation and handle the change with constant variables is still being determined. This manuscript calculates reference evapotranspiration (ET0) of the Red River Basin with a typical Alp-valley and elevation gradient from 1960 to 2021. Then at the scales of the whole basin, both sides of the main Alp (western of Ailao mountain (WAL) and eastern of Ailao mountain (EAL)), the mainstream valley (Yuanjiang valley (YJV)), the spatial–temporal distribution pattern of ET0 and its sensitivity of climate variables are depicted from the insights of barrier-corridor and elevation effects. The results indicate that ET0 grows at a rate of 27.77 mm per decade throughout the Red River Basin, China (RRBC), gradually declines from northwest to southeast, and increases with increasing elevation. The barrier effect of the Ailao Mountains within the RRBC alters the elevation distribution pattern of ET0 on both sides of the mountain. In contrast, the corridor effect along the YJV causes the ET0 increases with the depth of the valley. Accordingly, the aridity index increases with rising elevation resulting in drier climatic conditions in the north of the RRBC, and suffers a significant influence from Alp-valley topography resulting in wet WAL, dry EAL and drier YJV. The topography plays an impact on ET0 through the climatic control variables. Solar radiation (Rs) has the highest impact on ET0, followed in descending order by relative humidity (RH), air temperature (T) and wind speed (U). With the elevation increases, Rs and T reduce the effect on ET0, whereas RH increases its effect. Also, the barrier effect changed the dominant factors: Rs and RH control the ET0 on WAL and EAL, respectively, while the corridor effect enhances the role of T and U. Moreover, the schematic diagram of the ET0’s change with elevation gradient and Alp-valley, and its climate controls is deduced. This research can help us comprehend the spatial differentiation of ET0 in complicated topographical areas, as well as uncover its dynamic mechanisms under elevation and Alp-valley effects.

The tree cooling pond effect and its influential factors: A pilot study in Gold Coast, Australia

Residents were suffering from climatic issues resulting from global warming and urban heat islands (UHI). Researchers have explored ways of mitigating these issues. They have discovered several factors that adjust microclimate, including vegetation. Vegetation, especially trees, can significantly mitigate heat stress, often by providing canopied spaces. However, the temperature differences between various points under individual trees have rarely been investigated. The present study aimed to determine these temperature distribution patterns. A new concept, the tree cooling pond effect (TCP), was proposed and defined in a similar way to UHI. The level of TCP was represented by the mean radiant temperature (MRT) difference between four points in line with the direction of tree shade (A, next to the trunk; B, the midpoint between A & C; C, the margin of the shade; and D, 1 m away from C and in the sunshine). The MRT was measured and shown to increase slightly when moving from A to C, with a sharp increase between C and D. Physical characteristics of the trees, especially the tree crown diameter (TCD), impacted the incremental change (∆MRT) significantly. Through linear regression, it was found that ∆MRT was polynomially correlated with tree characteristics; e.g., TCD and distance from the trunk. For a tree with a TCD of 16.6 m, the ∆MRT between Point A and Point D was up to 18 °C; this result indicates that trees had insignificant cooling effects on the unshaded area (in the sunshine) despite neighbouring it. This study represents an initial effort; it visually illustrate tree cooling by identifying several critical points to delineate the pond, which has rarely been considered in previous studies.

Evolution Characteristics of Wetland Landscape Pattern and Its Impact on Carbon Sequestration in Wuhan from 2000 to 2020

The wetland ecosystem is an important organic carbon pool on earth, and rich carbon storage and high carbon density are present in wetland vegetation and soil. However, large areas of wetlands have been drained, the area of wetlands has shrunk, and the degree of fragmentation has intensified due to rapid urbanization in the past 20 years. Enhancing ecological carbon sequestration capacity is a key task of carbon peaking and neutrality, and studying the carbon sequestration function of urban wetland is urgently needed. In this work, the wetland in Wuhan was taken as the main research object. The landscape pattern index of Wuhan wetland was calculated and the evolution characteristics of landscape pattern were analyzed using the remote sensing image interpretation data from 2000 to 2020. CASA model was used to estimate the carbon sequestration of wetlands and explore the spatial and temporal distribution pattern of carbon sequestration. Spearman correlation was used to study the effects of different landscape pattern parameters on carbon sequestration. Results indicate the following: (1) From 2000 to 2020, the total wetland area in Wuhan has been reduced by 158.99 km2, among which the area of lakes, reservoirs and marshes decreased by 60.65 km2, 55.51 km2 and 41.77 km2, respectively. The density of wetland patches and the degree of fragmentation and irregularity increased, and the LPI, aggregation degree and diversity decreased. (2) In the past 20 years, the total carbon sequestration amount of wetland in Wuhan first decreased and then increased, among which the carbon sequestration in wetland was the lowest in 2010 (571,900 t). The amount of carbon sequestration in 2020 was the same as that in 2000, reaching 800,000 t. (3) A larger wetland area means more concentrated and denser distribution, more complex shape, more diverse type, and stronger carbon sequestration capacity for Wuhan wetland. On the contrary, the distribution of wetlands becomes more fragmented and regular, and the disordered planning leads to the reduction in wetland types in a unit area, which will decrease the carbon sink capacity of urban wetlands.

Моделирование технологических параметров процесса фрезерования заготовок деталей из поликарбоната при различных режимах обработки

Computer simulation of technological parameters in the milling process of polycarbonate workpieces under various processing modes is realized. The parameters are recorded at various points in the contact time of the milling cutter tooth with the workpiece. The regularities of changes in the parameters of the milling process, including forces and temperatures in the contact zones of the facing with the cutter tooth or in case of tooth contact with the workpiece, depending on the elements of the milling mode, are found. It’s also found that the temperatures in the contact zone of the tooth with the workpiece are higher than in the contact zone of the tooth with the facing. The pattern of temperature distribution in the surface layer of the workpiece is distilled. Mathematical dependences describing the relationship of temperatures with the elements of the milling mode, are obtained

A dynamic model for elevator operation-induced spread of a respiratory infectious disease in an apartment building

Residents have to use elevators to leave and enter their high-rise apartments frequently. An elevator car can easily spread respiratory infectious diseases, as it has a confined and small space. Therefore, studying how elevator operations promote epidemic transmission is of importance to public health. We developed an infectious disease dynamics model. First, we used homemade codes to simulate the operating state of an elevator and the dynamic process of infectious disease transmission in an apartment building due to elevator operations. Second, we analysed the temporal distribution patterns of infected individuals and patients. Finally, we validated the reliability of the model by performing continuous-time sensitivity analysis on important model parameters. We found that elevator operations can cause rapid spread of infectious diseases within an apartment building. Therefore, it is necessary to enhance elevator ventilation and disinfection mechanisms to prevent the outbreak of respiratory infections. Moreover, residents should reduce elevator use and wear masks.

Ecology, more than antibiotics consumption, is the major predictor for the global distribution of aminoglycoside-modifying enzymes.

Antibiotic consumption and its abuses have been historically and repeatedly pointed out as the major driver of antibiotic resistance emergence and propagation. However, several examples show that resistance may persist despite substantial reductions in antibiotic use, and that other factors are at stake. Here, we study the temporal, spatial, and ecological distribution patterns of aminoglycoside resistance, by screening more than 160,000 publicly available genomes for 27 clusters of genes encoding aminoglycoside-modifying enzymes (AME genes). We find that AME genes display a very ubiquitous pattern: about 25% of sequenced bacteria carry AME genes. These bacteria were sequenced from all the continents (except Antarctica) and terrestrial biomes, and belong to a wide number of phyla. By focusing on European countries between 1997 and 2018, we show that aminoglycoside consumption has little impact on the prevalence of AME-gene-carrying bacteria, whereas most variation in prevalence is observed among biomes. We further analyze the resemblance of resistome compositions across biomes: soil, wildlife, and human samples appear to be central to understand the exchanges of AME genes between different ecological contexts. Together, these results support the idea that interventional strategies based on reducing antibiotic use should be complemented by a stronger control of exchanges, especially between ecosystems.

Monitoring Multi-Scale Ecological Change and Its Potential Drivers in the Economic Zone of the Tianshan Mountains' Northern Slopes, Xinjiang, China.

Accurately capturing the changing patterns of ecological quality in the urban agglomeration on the northern slopes of the Tianshan Mountains (UANSTM) and researching its significant impacts responds to the requirements of high-quality sustainable urban development. In this study, the spatial and temporal distribution patterns of remote sensing ecological index (RSEI) were obtained by normalization and PCA transformation of four basic indicators based on Landsat images. It then employed geographic detectors to analyze the factors that influence ecological change. The result demonstrates that: (1) In the distribution of land use conversions and degrees of human disturbance, built-up land, principally urban land, and agricultural land, represented by dry land, are rising, while the shrinkage of grassland is the most substantial. The degree of human disturbance is increasing overall for glaciers. (2) The overall ecological environment of the northern slopes of Tianshan is relatively poor. Temporally, the ecological quality changes and fluctuates, with an overall rising trend. Spatially, ecological quality is low in the north and south and high in the center, with high values concentrated in the mountains and agriculture and low values in the Gobi and desert. However, on a large scale, the ecological quality of the Urumqi-Changji-Shihezi metropolitan area has worsened dramatically compared to other regions. (3) Driving factor detection showed that LST and NDVI were the most critical influencing factors, with an upward trend in the influence of WET. Typically, LST has the biggest influence on RSEI when interacting with NDVI. In terms of the broader region, the influence of social factors is smaller, but the role of human interference in the built-up area of the oasis city can be found to be more significant at large scales. The study shows that it is necessary to strengthen ecological conservation efforts in the UANSTM region, focusing on the impact of urban and agricultural land expansion on surface temperature and vegetation.

Temporal distribution and accumulation pattern of cadmium and arsenic in the actual field calcareous soil-maize system, northwest China

The contrasting chemical behaviors of two toxic elements, arsenic (As) and cadmium (Cd) in co-contamination calcareous soil and its absorption by crops have not been thoroughly explored, especially in the implementation of the measure of prohibiting the use of wastewater to irrigate farmland. We propose that the present environmental characteristics of ecologically fragile areas and appropriate restoration measures are critical determinant of soil remediation. In this study, the typical field farmland irrigated by industrial and domestic wastewater in the Chinese Loess Plateau for >50 years was selected. The results showed that after the sewage irrigation was stopped, the mean contents of Cd (7.09 mg/kg) and As (13.47 mg/kg) in the soil were still rising, which might be a potential input source. The average values of soil risk indices such as the potential ecological risk (PERI = 2394), pollution load index (PLI > 4 for 60 % of studied samples), and degree of contamination (Dc = 86.6) showed severe soil pollution in the study area. The decrease of soil pH, the loss of soil texture and calcium carbonate were found to be the reasons for the high chemical activity of Cd. The bioconcentration factors (< 0.2) and translocation factor (> 1.0) of Cd indicate that corn is an excluder plant and an ideal phytoremediation method. Thus, 20 % of studied samples were higher than maximum permitted levels of Cd in grain, indicating potential related health hazards. On the contrary, As was mainly adsorbed in calcareous soil, and its bioavailability was lower compared with Cd. The difference between DTPA extraction and sequential extraction may be due to the transformation of chemical forms, resulting in unstable fractions increased the bioavailability of toxic elements. Overall, the findings provide new insights for solutions to manage and repair farmlands under the post-wastewater irrigation period.

Spatial-Temporal Distribution Pattern and Tourism Utilization Potential of Intangible Cultural Heritage Resources in the Yellow River Basin

In this study, the spatial-temporal distribution pattern and tourism utilization potential of national ICH are analyzed based on GIS technology in the Yellow River Basin. The results show that: (1) The national ICH of the Yellow River Basin is distributed in an aggregated spatial pattern with the characteristic of “one belt and two cores”. The cities in Shanxi, Henan and Shandong provinces constitute the high-density and sub-high-density continuous belts. Haidong and Chengdu are the high-density and sub-high-density core areas, respectively. (2) The five batches of national ICH present a temporal distribution pattern of “Northeast to Southwest”. The distribution scope of national ICH in medium and high-density areas expands gradually and finally tends to be balanced. (3) For the single-factor evaluation of tourism utilization potential, there is an obvious gap in the evaluation grade among the cities. However, for the comprehensive evaluation of tourism utilization potential, there are 72 cities with an evaluation grade of three or above, accounting for 63%. This indicates that the tourism utilization potential of the national ICH in this basin is great. (4) The national ICH tourism in this basin can be developed from two aspects: regional differential development and regional linkage development.