Proportion Of Area Research Articles

Detrital clay mineral input reconstructed based on weathering records and its influence on organic matter enrichment: A case study of the Paleogene Shahejie Formation in the Dongpu Sag, Bohai Bay Basin

As major components of shales, clay minerals are important for investigating unconventional petroleum geology. However, there are few quantitative methods for investigating possible inputs of clay minerals during sedimentary processes. In this study, shales from the Shahejie Formation in the Dongpu Sag, Bohai Bay Basin, were chosen for investigating clay mineral inputs. The shales are abundant in a variety of clay minerals. The shales, uniformly derived from felsic igneous rocks, underwent mild K metasomatism. Thus, the detrital clay mineral input was primarily influenced by weathering intensity. Accordingly, representative samples subjected to varying weathering intensities were selected to identify detrital and diagenetic clay minerals. Kaolinite and chlorite are of detrital origin. Illite and illite/smectite mixed layers (I/S) have both detrital and diagenetic origins. The precursor minerals of diagenetic minerals can be identified based on their morphological and elemental characteristics. After quantifying the area proportions of various clay minerals, the detrital clay mineral compositions of selected samples were calculated. Further analysis indicated that the detrital illite content and the detrital chlorite content are closely related, while the detrital smectite content correlates well with the chemical index of alteration (CIA). Based on the preceding analysis, the fitting formulas were established to quantitatively characterize the input of detrital clay minerals. The shales from the north sag had a high input of detrital smectite, whereas the shales from the south sag had a high input of detrital illite. Consequently, the shales from the north sag contain more organic matter than those from the south sag.

An in situ combustion carbon deposit diagnostic instrument based on Raman microscopy.

Carbon deposit of the aero-engine combustor, resulting from incomplete combustion and fuel pyrolysis, can cause nozzle blockage, fuel consumption increase, power decrease, and even flight unsafety. In this work, an in situ combustion carbon deposit diagnostic instrument is developed to reveal the crystalline structure and the changes under real combustion conditions. The instrument integrates the in situ microscopic Raman technique and the combustion system. The burner is characterized by a sloping tip, making it possible to observe the coke from the side view. The burner is installed to the optical positioning stage by a specially made adapter so that the relative location is fixed and it is possible to observe the carbon deposit from the ignition. The carbon deposit of acetylene/air diffusion jet flame was studied. A 50× objective lens was used to collect the Raman scattering signal of carbon deposits continuously 30s after ignition. A five-band model was used to fit the Raman spectra. The time-resolved information was calculated, including the normalized total area, area proportion, peak ratio, and crystalline size. The results show that the carbon deposit of acetylene flames with different velocities presents different tendencies of formation and degree of graphitization, which is attributed to the influence of temperature and flow. The performance of this system is evaluated quantitatively. The signal-to-noise ratio of Raman spectra of carbon deposits ranges from 6.4 to 28.9. This work provides an in situ method to analyze the dynamic change of carbon deposit on the burner, and further work is needed to reveal the mechanism.

Supercritical Methane Adsorption Characteristics and Pore Structure Characteristics of Deep Middle Rank Coal

Abstract In order to accurately analyze the adsorption characteristics, pore structure, and fractal law of deep middle rank coal, high-pressure isothermal adsorption tests based on magnetic levitation high-pressure thermobalance and pore structure tests based on mercury intrusion method were carried out on coal samples collected from typical kilometer level deep wells. The fractal law of sponge model was studied. The results showed that: a. The weight method adsorption test showed “excess adsorption” phenomenon with the increase of equilibrium pressure, and the modified Gibbs surface excess adsorption theory was in line with the Langmuir adsorption model; b. The distribution of macropore volume in deep middle rank coal accounts for a dominant proportion of 57.44% to 62.47%, and the proportion of microporous specific surface area reaches 72.96% to 74.27%, indicating that microporous adsorption capacity is the strongest; c. The pore structure parameters and adsorption constants exhibit strong nonlinear characteristics.

Exploring the Potential Relationship between Cooling Green Space and Built-up area: Analysis of Community Green Space Characteristics Based on GWPCA

Rapid urbanization exacerbates urban heat island (UHI) problem. Although urban green space (UGS) can produce multiple benefits for mitigating UHI, the accompanying problems of urban development cause multiple pressures on greenery. Therefore, the pattern of green spaces should be adjusted to adapt to the current situation of the built-up area, fully utilizing its cooling effect, which is of great significance for achieving sustainable and balanced urban development. We selected 849 community units in Harbin city for the study, calculated the urban green space pattern index (UGSP) based on geographically weighted principal component analysis (GWPCA), And used bivariate choropleth map and Cartesian coordinate system to explore the spatial relationship between UGSP and associated characteristics of urbanization (e.g., land function diversity and development intensity). The results showed the following. (1) Compared with traditional PCA, GWPCA can capture local details of UGSP, especially proportion of tree area was the most sensitive factor in the urban core area, and FRAC_MN and LSI were the sensitive factors in the west and south of urban outer areas, respectively. (2) The matching degree between development intensity (I) and UGSP was slightly better than that between land function diversity (D) and UGSP, and showed a more egalitarian phenomenon. (3) The equilibrium value (dLow) presented a relatively random spatial distribution when UGSP was less than D/I, and the unbalanced value (dHigh) was scattered in the core area. Both dLow and dHigh were concentrated outside the urban core area when UGSP was greater than D/I. Our study provides an effective guidance for community greenery to mitigate UHI and realize the harmonious coexistence between city and nature.

The Law of the Total Pressure Loss in Supersonic Streamwise Corner Flow

Abstract The total pressure loss is a critical issue in the design of internal flow channels for hypersonic vehicles. In the flow through the streamwise corner region, the adjacent walls induce secondary flows that exacerbate the viscous effects, thereby intensifying the total pressure loss. This study investigates the impact of the corner’s dihedral angle and the compressibility of the flow on the total pressure loss in the streamwise corner region. The results indicated that as the dihedral angle increases, the distribution of the total pressure contour in the corner region became significantly distorted. The proportion of the boundary layer area within the corner region concurrently increased as the dihedral angle deviates from 90 degrees. Furthermore, we deduce that the total pressure loss is the largest in the supersonic flat plate boundary layer. This paper normalized the total pressure loss coefficient for different dihedral angles in the corner region and established an empirical relationship for the distribution of normalized total pressure loss coefficients along the flow path. It is discovered that under supersonic inflow conditions, the distribution law of the total pressure loss in the corner region exhibits higher predictive accuracy.

Ecosystem services driving factors and ecological conservation pattern construction, Qinghai-Tibet Plateau

Given that the Qinghai-Tibet Plateau (QTP) is an important ecological security barrier in western China, changes in its ecosystem services (ESs) have received attention. Using multivariate datas and model simulations, we evaluated the ESs of the QTP, revealed their driving factors, and constructed ecological conservation pattern based on ecosystem services index (ESI) and ecosystem sensitivity (ES). The results showed that: (1) The overall ESs of the QTP from 2000 to 2020 were positive, with a spatial distribution characteristic of decreasing from southeast to northwest. Forest and grassland were the key land use types promoting ESs. (2) Natural factors had a stronger influence on ESs than socioeconomic factors, with precipitation, FVC (Fractional Vegetation Cover) and NPP (Net Primary Productivity) had the strongest explanatory power for ESs. (3) The proportion of the collaborative development area (CDA), consolidation and enhancement area (CEA) and priority protection area (PPA) to the total area of the QTP was 19%, 56% and 25% respectively. The CDA should follow the concept of natural restoration and green development. The CEA should optimize the management system and do a good job of environmental management in combination with artificial restoration. The PPA should strictly prevent disturbances caused by human activities and protect the originality of natural landscapes such as glaciers, snow and permafrost.

Characterizing Ecological Sensitivity of Yangtze River Delta Urban Agglomeration in China

Ecological sensitivity, as one of the most important indicators to evaluate regional environmental issues, holds significant implications for ecological governance and management in the related area. This study utilized remote sensing imagery of Landsat Thematic Mapper (TM) from the Yangtze River Delta (YRD) in 2014 and 2018, combined with field surveys and socio-economic data. Considering the local ecological and environmental conditions in the region, nine factors related to seven aspects, soil erosion, topography, humidity, habitat, water environment, human interference, and climate, were selected to create an ecological sensitivity evaluation framework for the YRD urban agglomeration. The coefficient of variation method was applied to determine factor weights, while the zonal statistics and spatial overlay methods were used for a comprehensive analysis of ecological sensitivity in a geographic information system (GIS). The YRD urban agglomeration was categorized into five ecological sensitivity levels: extremely sensitive, highly sensitive, moderately sensitive, slightly sensitive, and insensitive. The analysis results revealed spatial variations in the distribution of ecological sensitivity across the YRD urban agglomeration, with the overall ecological sensitivity level being slightly sensitive. The proportions of the total area occupied by extremely sensitive, highly sensitive, moderately sensitive, slightly sensitive, and insensitive zones were 14.30%, 12.02%, 25.29%, 30.34%, and 18.05% in 2014, and 14.30%, 24.01%, 16.33%, 27.32%, and 18.05%, respectively, in 2018. Based on these results, relevant ecological vulnerabilities for the YRD urban agglomeration were discussed.

Surprisingly good fit of pressure-based cropland condition map and bird census data at the national scale

As the world is struggling to halt the rapid decline of biodiversity, the assessment and mapping of ecosystem condition is getting ever increasing attention. Croplands are artificial ecosystems, but as they occupy a large portion of land, they significantly influence biodiversity. Yet, there is a knowledge gap about their suitability to support and maintain wildlife on a national scale. Large-scale condition mapping is meant to address this gap; the good condition of croplands includes their ability to support biodiversity. However, the lack of suitable databases is often a challenge when creating such maps. As there is a strong causal relation between pressures on the ecosystem and its condition, pressure indicators can be used as proxies to approximate condition when more direct indicators are lacking. The validation of condition maps based on pressure proxies is a key but challenging step. In this study, we tested a previously designed pressure-based cropland condition map for Hungary using bird census data. Besides validating the composite condition indicator, we also tested some key elements of the mapping process, such as the choice of variables and thresholds.Using multiple comparisons of means by Tukey’s contrast and Random Forest modelling, we examined the relationship of (1) the continuous pressure-based cropland condition variables, (2) their rescaled, ordinal version (called sub-indicators), and (3) the composite cropland condition indicator (sum of the sub-indicators) with a biodiversity measure, the standardised relative richness of characteristic farmland bird species (rRRCS). To get a picture of the spatial patterns of the examined relationships across Hungary, individual Random Forest models were constructed for all the spatial units of the bird census database, using focal analysis with a 30 km radius moving window.We found significant differences in the mean rRRCS for nearly all sub-indicator categories, signifying that the literature-derived thresholds were mostly sound. Categories with higher (better) condition scores had higher mean rRRCS; the differences are significant in the mid-range but not in the extreme categories, indicating a need for a meaningful simplification of the categories. The goodness-of-fit (R2) of the Random Forest models was found to be high, but it is spatially heterogeneous (ranged from 0.69 to 0.89, with a median value of 0.81), similarly to the variable importance. The proportion of semi-natural areas proved to be the most important condition variable. The proportion of maize and alfalfa were more important than parcel size. Our results show that condition maps based on pressure proxies can reflect patterns of biodiversity surprisingly well. They also highlight the spatial context dependence of the uncertainty of condition maps.

A method for evaluating the visual quality of wetland park landscapes: a case study of qianlu lake wetland park in Wuping, China

Wetland parks are an important part of urban ecosystems, characterized by artificial and natural features. While providing outdoor recreational space for urban residents, the aesthetics of the landscape also affect residents’ willingness to visit the wetland park. Previous studies of wetland parks focused on the ecological benefit. However, fewer systematic studies analyzed the aesthetic qualities and influencing elements of wetland parks. In this study, the Wuping Qianlu Lake Wetland Park in Fujian Province, China was used to evaluate the landscape visual quality of the wetland park using the the Scenic Beauty Estimation method (SBE), and the landscape features of the wetland park were obtained through the Semantic Differential (SD) method and semantic segmentation technique. The regression model of landscape visual quality and landscape features in wetland parks was established using SBE values as the dependent variable, and 23 landscape features as independent variables. The SBE values and accessibility were also combined to create four quadrants, which were combined with K-means clustering to diagnose existing problems. The results of the study showed that two landscape features, approach and proportion of water area were weaker among the four types of wetland park landscapes. The SBE values of the man-made landscape type were the most significant. Meanwhile, the high enclosure landscape type had a significant sense of rusticity, accentuating the wildness of the plants. It was less aesthetically pleasing and had the poorest landscape visual quality of the four types. This study provides a systematic method for diagnosing landscape problems in wetland parks, evaluating landscape visual quality assessment, and providing theoretical and technical support for urban wetland park renewal and construction.

Prognostic Value of Pulmonary Artery Systolic Pressure in Severe Rheumatic Mitral Stenosis.

Current guidelines recommend intervention for asymptomatic rheumatic mitral stenosis (MS) with mitral valve area ≤1.5 cm2 based on indicators including pulmonary arterial systolic pressure (PASP) >50 mm Hg and new-onset atrial fibrillation; however, evidence supporting this is lacking. This single-center retrospective study included patients with rheumatic MS between 2006 and 2022. Pulmonary hypertension was evaluated by using echocardiography to estimate PASP. Primary outcomes were major adverse cardiovascular events (MACE), including all-cause mortality, hospitalization for heart failure, and arterial thromboembolic events for up to 5 years. Overall, 287 patients with severe rheumatic MS were enrolled (mean age, 62.5±11.3 years; 74.6% women). During a median follow-up of 2.52 years, MACE occurred in 99 patients. There were no differences in echocardiographic parameters, such as the mean mitral valve pressure gradient, mitral valve area, and proportion of mitral valve area <1.0 cm2, between patients who developed primary outcomes and those who did not. Survival analysis showed a worse prognosis in patients with estimated PASP (ePASP) >50 mm Hg than in those with ePASP ≤50 mm Hg (log-rank P<0.001); however, atrial fibrillation was not a significant prognostic indicator. As a continuous variable, ePASP (mm Hg) was a significant predictor of MACE (adjusted hazard ratio, 1.027 [95% CI, 1.011-1.042]; P<0.001). Receiver operating characteristic analysis revealed an optimal ePASP threshold of >45 mm Hg, which was an independent predictor of MACE in patients with severe rheumatic MS (adjusted hazard ratio, 2.127 [95% CI, 1.424-3.177]; P<0.001). Competing risk analysis considering mitral valve intervention as a competing risk showed similar results. Our study demonstrated the prognostic significance of ePASP, rather than atrial fibrillation, in relation to MACE among patients with severe rheumatic MS. Additionally, we proposed a lower ePASP threshold (>45 mm Hg) as a predictor of an unfavorable prognosis.

Spatiotemporal characteristics and socio-ecological drivers of ecosystem service interactions in the Dongting Lake Ecological Economic Zone

Uncovering the spatiotemporal characteristics of ecosystem services and their complex interactions is a prerequisite for managing multiple simultaneously. However, the prior research has predominantly overlooked cultural service objects and neglected the indirect socio-ecological impact pathways on ecosystem services. To delve into the dynamics and developmental trends of ecosystem alterations prior to and following the inception of an Eco-Economic Zone, this study quantitatively assessed four pivotal ecosystem services within the Dongting Lake Ecological Economic Zone spanning from 2000 to 2020. These services encompassed:crop production(CP), carbon sequestration(CS), habitat quality(HQ), and forest recreation (RS). The trade-offs and synergies between them were explored, and the driving mechanism of ecosystem services was explained based on the partial least squares-structural equation model (PLS-SEM). The results revealed that: (1) during the study timeframe, the crop production witnessed a pronounced upward trajectory, whereas the carbon sequestration, habitat quality and forest recreation remained relatively stable. Notably, the low habitat quality area (HQ ≤ 0.3) has been expanding, with a growth rate of 29.4 %; (2) the most trade-offs were observed between crop production and other ecosystem services, among which the trade-off effect between crop production and habitat quality was the strongest, with the highest average proportion of trade-off area, reaching 57.8 %. Among the six ecosystem service pairs, two are in a state of deterioration: the crop production and forest recreation, the carbon sequestration and habitat quality; (3)topographic factors were identified as the primary drivers of crop production, carbon sequestration, and habitat quality, whereas forest recreation was chiefly influenced by landscape configuration factors. Land use intensity and landscape configuration played crucial intermediary roles, with socio-economic elements adversely impacting all four ecosystem services directly, yet significantly contributed to the crop production and carbon sequestration through Suppression Effects. The research endorses the combined utilization of lake area land to improve human welfare, based on the principle of protecting the primary services of various functional sub-regions.

Effects of habitat fragmentation on ecosystem services and their trade-offs in Southwest China: A multi-perspective analysis

Exploring the relationships between habitat fragmentation on ecosystem services (ESs) is important for ecological conservation and spatial pattern optimisation. However, analyzing the influence of different habitat fragmentation processes on ESs and their trade-offs from a multiple perspective is still relatively lacking. Therefore, taking Southwest (SW) China as an example, this paper evaluated the dynamics and trade-off relationship of four main types of ESs (i.e., carbon storage (CS), grain production (GP), water retention (WR), soil retention (SR)) during 2000–2020, and analyzed the effects of four habitat fragmentation processes (i.e., decreasing habitat area, increasing habitat density, increasing habitat shape complexity and decreasing habitat cohesion) on ESs and their trade-offs by using geographically and temporally weighted regression model. The results showed that ESs showed a deterioration trend during 2000–2020, with GP, WR, CS, SR, and total ecosystem services (TES) declined by 66.45 %, 54.33 %, 41.68 %, 76.25 % and 65.83 %, respectively. The GP-SR, GP-CS and GP-WR pairs exhibited trade-offs, while other ES types pairs exhibited synergies with each other. Increasing habitat density and increasing in habitat shape complexity were the two strongest fragmentation processes influencing ESs and their trade-offs. The effects of various habitat fragmentation processes on ESs and their trade-offs have obvious spatial heterogeneity. With changes in terrain relief, proportion of karst area, habitat quality, and urbanization level, the association of habitat fragmentation-ESs and habitat fragmentation-ESs trade-offs existed different sensitivities. The results can provide effective guidance for landscape planning and ecosystem management in the SW.

Topical Application of 0.05% Cyclosporine for the Treatment of Neurotrophic Keratopathy Secondary to Herpes Simplex Keratitis

The purpose of this study was to assess the effectiveness and tolerability of 0.05% cyclosporine A (CsA) eye drops for neurotrophic keratopathy (NK) secondary to herpes simplex keratitis (HSK). Fifteen patients (15 eyes) with prior HSK and secondary NK, classified as stage 2 or 3 on the basis of the Mackie classification, were enrolled. All patients received a combined treatment regimen of 0.05% CsA eye drops (1 drop 4 times daily), a silicone hydrogel bandage contact lens, and 0.15% ganciclovir ophthalmic gel (1 drop 3 times daily). For patients achieving corneal healing, CsA was continued at a reduced dosage of twice daily for an additional 2 months and other treatments were discontinued. Follow-ups were scheduled at weeks 1, 2, 3, and 4 and at months 2 and 3 after treatment initiation, followed by a 3-month follow-up period. Key outcomes, including best-corrected visual acuity, Schirmer I test, and corneal sensitivity, were assessed at each visit before and after treatment. Significant reductions were observed in the area of corneal defects, expressed as proportion of total corneal area, throughout follow-up period. Complete corneal healing was achieved by 13.3% of patients by week 2, 60.0% by week 3, 86.7% by week 4, and 100.0% by week 8, with the mean (SD) time to healing being 3.8 (1.8) weeks (range, 2-8 weeks). Additionally, significant improvements were noted in diseased eyes for best-corrected visual acuity, tear secretion (Schirmer I test values), and corneal sensitivity after treatment. CsA eye drops, with bandage lenses and ganciclovir, effectively resolve NK from HSK, without adverse effects. This combination therapy shows promise for future clinical use and research. Our study is a retrospective observational study because it involves the analysis of previously collected data, so the study was not registered prior to its commencement. However, if it is necessary for publication, we are willing to proceed with retrospective registration.

Cerebellar Molecular Signatures in Non-Human Primates.

Cerebellar molecular signatures in primates remain largely unexplored. Here, we investigated the immunoreactivity of neuroplasticity-related molecular markers, including aldolase C (Aldoc), phospholipase C beta 3 (PLCB3), and phospholipase C beta 4 (PLCB4) in the cerebellar cortex and associated nuclei of rhesus macaque monkeys (Macaca mulatta). Our main findings are as follows: First, the cerebellar vermis in macaques exhibited striped compartmentalization for all markers, with the striped expression boundary of PLCB3 being less distinct than those of Aldoc and PLCB4. Second, the striped pattern was less pronounced in the cerebellar hemisphere compared to the vermis, with signals in the hemisphere being predominantly intense throughout. Third, distinct zonal patterns and elevated signals for Aldoc and PLCB3 were observed in the cerebellar deep nuclei. Specifically, the fastigial nucleus displayed intense Aldoc signals in both caudal and rostral regions, while the dentate nucleus displayed strong Aldoc signals in both ventral and dorsal regions. Compared to previous rodent studies, the macaque cerebellum demonstrated a higher proportion of intense signal areas and distinct compartmentalization patterns in both cortical and deep nuclei. These findings offer crucial insights into the unique molecular organization of the primate cerebellum, enhancing our understanding of the advanced neuroplasticity, cognitive, and motor capabilities in primates.

Two-Dimensional Physical Model Experimental Study on Sweep Efficiency of Offshore Heavy Oil Hot Water Flooding

Abstract The conventional water flooding approach for the development of ordinary heavy oil faces challenges such as high injection-production mobility, rapid increase in water cut, and low final recovery. By using the temperature-sensitive properties of heavy oil, the viscosity can be effectively reduced, and the flow capacity within porous media can be enhanced by increasing the temperature of injected water. Onshore hot water flooding is primarily used to exploit the remaining oil potential during the later stages of steam stimulation, while offshore is used to enhance efficiency during the mid to late stages of water flooding. The key to the success of hot water flooding technology lies in the improvement of the sweep coefficient. Firstly, a two-dimensional physical experiment model is designed in accordance with the geological and reservoir characteristics of the target oilfield, based on the principle of similarity. Secondly, parameters that quantitatively characterize the development law of the plane temperature field, such as the effective sweep coefficient, regular factor, and plane expansion speed of the high-temperature region, are studied. Then, through two-dimensional experiments, the effects of injection medium, formation rhythm, and timing of hot water injection on sweep efficiency and temperature field development were discussed. Finally, on the basis of two-dimensional experiments, the effects of heat injection temperature, timing of heat injection, hot water injection speed, and high permeability strip on the improvement of sweep efficiency were quantitatively analyzed by numerical simulation. The results show that compared with hot water flooding, hot water composite flooding can increase the effective sweep coefficient from 15.05 % to 28.71 %. The anti-rhythm is helpful to the upward expansion of the high temperature zone, which can increase the oil displacement efficiency by 1.5 %. Water channeling can be effectively controlled by injecting hot water with low water cut. The increase of heat injection temperature is helpful to increase the proportion of high temperature heating area. The higher the injection speed, the greater the expansion speed of the heating chamber. The research results provide a direction for the development of heavy oil conventional water flooding to improve oil recovery in offshore heavy oil.

Analyzing the spatial scale effects of urban elements on urban flooding based on multiscale geographically weighted regression

In the context of rapid urbanization and the frequent occurrence of extreme rainfall in cities, the risk of flooding in the future will further increase, and the problem of urban flooding cannot be ignored. Urban elements exhibit significant spatial heterogeneity, which largely determines the spatial distribution differences in urban flooding. Therefore, it is important to clarify the scale of influence of different urban elements and explore their scale effects on urban flooding to accurately assess the risk of urban flooding. Taking Zhengzhou City, China, as the study area, this study analyzed the urban elements associated with urban flooding, quantified the scale of the influence of urban elements on flooding using multiscale geographically weighted regression (MGWR), and further explored the spatial scale effects of urban elements on urban flooding. The results showed that MGWR can better fit the spatially non-uniform distribution of urban flooding and that the scale of the influence of urban elements on urban flooding can be reflected by the bandwidth of MGWR. The results of MGWR indicated that the bandwidths of elevation, number of drainage outfalls (NDO1Abbreviations: RRP, Rainfall return period; DDR, Distance to river; NDO, Number of drainage outfalls; ILMFCP, Input level of materials for flood control projects; PRL, Proportion of residential land; PCL, Proportion of commercial land; PIL, Proportion of industrial land; PPSL, Proportion of public service land; PRA, Proportion of road area; PGL, Proportion of green land; PD, Population density; MI, Manpower input; GDP, Gross domestic product; ILER, Investment level in education and research.1), distance to river (DR), Gross domestic product (GDP), proportion of residential land (PRL), and proportion of commercial land (PCL) were small, and their influence scales were localized. In contrast, the influence of rainfall return period (RRP), slope, proportion of industrial land (PIL), proportion of public service land (PPSL), proportion of road area (PRA), proportion of green land (PGL), input level of materials for flood control projects (ILMFCP), population density (PD), manpower input (MI), and investment level in education and research (ILER) were at global scales. The most influential factors for urban flooding were RRP, PD, and MI. Slope, DR, and PRA had less influence on urban flooding. This study helps improve the effectiveness of urban flood prevention and mitigation efforts.

Influence of urban functional zone change on land surface temperature using multi-source geospatial data: A case study in Nanjing City, China

The urban heat island effect is a prevalent urban concern, and studies on its influencing factors are essential to mitigate its negative effects and promote sustainable urban development. Although many studies have revealed the impact of land cover change on land surface temperature (LST) during urbanization, most have focused only on built-up areas without considering the relationship between urban internal functional structure and LST. To clarify the influence of changes in urban functional zones (UFZs) on LST, focusing on the downtown area of Nanjing City, China, this study proposed an effective framework using multi-source geospatial data for qualitative and quantitative analysis. Specifically, very high spatial resolution images and point of interest data were jointly used to generate UFZ maps using an advanced deep learning approach, and LST distribution maps were retrieved from Landsat 8 images using the radiative transfer equation. The UFZ and LST maps were then overlaid and analyzed to reveal the impact of UFZ change on LST. The results showed that in 2013, 2018, and 2022, the residential region constituted the largest proportion of area, comprising 23.52%, 24.52%, and 27.28%, respectively. The areas of unused region and transport region experienced the most rapid decrease and increase of 6.08% and 4.05% from 2013 to 2022, respectively. Furthermore, the area of sub-high temperature zone decreased the most, by 3.47%, whereas that of the high-temperature zone increased the most, by 6.05%. In the study area, water and green space maintained relatively low LSTs, whereas residential region and unused region exhibited higher LSTs. From 2013 to 2022, UFZ changes contributed to a 0.71°C increase in LST. Transfers from green space, water, commercial region, transport region, and industrial region mostly resulted in a higher LST, which was associated with a decrease in fractional vegetation cover (FVC). Transfers from unused region, residential region, and public service region mostly contributed to reducing LST, which was caused by the increase in FVC. The findings and the proposed framework can provide reliable references for urban managers to optimize urban spatial layout and promote sustainable urban development.

Contrasting foliar nitrogen nutrition of coexisting temperate and boreal trees across a modest temperature cline

The temperate-boreal forest ecotone represents a transition zone from temperate to boreal forest where nitrogen (N) is frequently limiting tree growth, which is highly sensitive to climate change. However, the spatial patterns and potential drivers of plant N nutrition and soil N availability remain poorly understood. To address this, we conducted a field investigation along a temperate-boreal forest ecotone in northeastern China, characterized by a modest mean annual temperature gradient (∼1°C) within the range of current climate warming. Our goal was to evaluate the spatial variation in foliar N nutrition and soil N availability, and the potential driving factors for Mongolian oak (Quercus mongolica) and Dahurian larch (Larix gmelinii), the dominant trees of the local temperate and adjacent boreal forests, respectively. Our results revealed no significant spatial trend in topsoil N availability across the sampling transect. Overall, foliar N concentration was significantly higher, but foliar δ15N was lower, for Mongolian oak than Dahurian larch. More important, foliar N concentration for Mongolian oak increased significantly toward the boreal forest, driven by lower mean annual temperatures and mean annual precipitation, with no significant trend observed for Dahurian larch. Additionally, foliar Δδ15N (foliar δ15N−soil δ15N) decreased significantly for Mongolian oak as it approached the boreal forest, while it increased significantly for Dahurian larch toward the temperate forest. Furthermore, the foliar N concentration, δ15N, and Δδ15N for Dahurian larch were all higher with an increasing basal area proportion of Mongolian oak. Our findings reveal contrasting patterns of foliar N nutrition between co-occurring temperate and boreal trees across a temperate-boreal forest ecotone which experiences a modest climatic gradient. These results underscore the importance of incorporating interspecific interactions to enhance our understanding of future N cycling in southern boreal forests in the context of climate warming.

An Indoor Air Quality Analysis in Newly Constructed Apartments

This study analyzes the indoor air quality inspections of newly constructed apartments by the Busan Institute of Health and Environment for the last three years (2021-2023). Of the 41 inspections, 33 exceeded the recommended standard, and the average excess rate was 80.5%. When classified by measuring households, 148 out of 332 exceeded the standards, whereas, the average excess rate by household was 44.6%. Benzene was exceeded in two out of the 332 households; therefore, the excess rate was only 0.6%. However, the relative standard deviation was the largest, showing as the highest item in the scattergram. The average concentration of toluene was 1,006.0 µg/m3, which was 100.6% of the recommended standard and was exceeded by 138 households; hence, the excess rate was 41.6%. All six items(Formaldehyde, Benzene, Toluene, Ethylbenzene, Xylene, Styrene) reached the highest concentration in spring or summer when the indoor temperature increased. The average concentration of toluene in July was 1,922 µg/m3, close to 1.9 times the recommended standard; toluene is considered an item of particular concern in summer. In the correlation analysis with indoor temperature, the formaldehyde coefficient of determination was 0.4855, regarded as somewhat significant; it was difficult to confirm the correlation with temperature for the other five items, including benzene. In correlation with relative humidity, formaldehyde showed the same tendency as indoor temperature, with a coefficient of determination of 0.4404, which is believed to be due to its small molecular weight and high solubility. Due to the chimney effect, high concentrations of volatile organic compounds could be confirmed at low atmospheric pressure in the upper floors, and this trend was most evident for formaldehyde. For most items(Formaldehyde, Benzene, Toluene, Ethylbenzene, Styrene), a negative correlation was confirmed in which the emission amount decreased as the number of households increased. For large apartment houses, it is believed that it is due to sufficient bake-out and flush-out according to the adequate construction period and the use of eco-friendly and high-end building materials. Small apartments are classified together with many small houses. The emission concentration of small houses is relatively high because the proportion of the surface area where pollutants are released is high.

Alkali Metal Cations Induce Structural Evolution on Au(111) During Cathodic Polarization.

The activity of the electrocatalytic CO2 reduction reaction (CO2RR) is substantially affected by alkali metal cations (AM+) in electrolytes, yet the underlying mechanism is still controversial. Here, we employed electrochemical scanning tunneling microscopy and in situ observed Au(111) surface roughening in AM+ electrolytes during cathodic polarization. The roughened surface is highly active for catalyzing the CO2RR due to the formation of surface low-coordinated Au atoms. The critical potential for surface roughening follows the order Cs+ > Rb+ > K+ > Na+ > Li+, and the surface proportion of roughened area decreases in the order of Cs+ > Rb+ > K+ > Na+ > Li+. Electrochemical CO2RR measurements demonstrate that the catalytic activity strongly correlates with the surface roughness. Furthermore, we found that AM+ is critical for surface roughening to occur. The results unveil the unrecognized effect of AM+ on the surface structural evolution and elucidate that the AM+-induced formation of surface high-activity sites contributes to the enhanced CO2RR in large AM+ electrolytes.