•We examined the land use/land cover changes（LUCC) during 2000–2020.•The multi-scenario land-use spatial patterns were optimized and simulated with Markov-PLUS and MOP-PLUS.•We assessed the ecosystem ...service value (ESV) with a spatially modified ESV assessment model.•Identify drivers that determine ESV spatial stratified heterogeneity with geographic detectors.•LULC conversion of 1% would result in average changes of 0.43% in ESV, and the responses of ecosystem services to LUCC were not very marked.
High-intensity human activities have changed land use/land cover (LULC) patterns in the Huangshui River Basin (HRB), which has brought significant challenges to ecosystems sustainable development. Discerning ecosystem service dynamic characteristics and responses under different land use/cover change (LUCC) scenarios are necessary to increase the public willingness to pay for the ecosystem and guide the decision-making process. We examined LULC spatiotemporal dynamics in the HRB from 2000 to 2020 and coupled Markov-chain, multi-objective programming (MOP), and patch-generating land use simulation (PLUS) models to optimize and simulate LULC spatial pattern for five scenarios: natural development scenario (NDs), city expansion scenario (CEs), ecological protection scenario (EPs), economic development scenario (EDs), ecological and economic balance scenario (EEBs). Given regional differences, a spatially modified ecosystem service value (ESV) assessment model was proposed to evaluate ESV. Factors driving ESV spatial stratified heterogeneity were identified using geographic detectors. Ecosystem service value sensitivity in response to LUCC was discriminated against using the elasticity model. The study area was dominated by 56.86–60.40 % grassland and 33.11–36.27 % cropland. Grassland and cropland area decreased by 579.75 km2 and 423.87 km2 over the period 2000–2020, while the other areas such as forestland, water area, construction land, and barren land increased by 289.81 km2, 140.77 km2, 489.10 km2, and 83.96 km2, respectively. Land conversion mainly occurred among grassland, cropland, and construction land. Total ESV was 39,665 million yuan in 2020, an increase of 2.25 % compared to 2000. Total ESV of NDs, EPs, EDs, and EEBs increased by 0.34 %, 1.04 %, 2.01 %, and 7.78 %, respectively compared to 2020, while that of CEs decreased by 0.17 %. ESV sensitivity coefficient response to LUCC was 0.43 during 2010–2020, indicating that LULC conversion of 1 % would result in average changes of 0.43 % in ESV. Ecosystem services response to LUCC was not very marked in the HRB. Elevation was the dominant driver of LULC and ESV stratified spatial heterogeneity in the HRB. The effects of elevation on LUCC and ESV should receive more attention in management. Multi-objective optimization and multi-scenario analysis effectively guided land-use planning and decision-making involved in ecosystem uncertainty, complexity, and interaction. The EPs and EEBs may be more suitable for future HRB development.
Because unmanned aerial vehicle aerial images are captured at high altitude, they contain objects at different viewpoints and in different states, resulting in two major problems in the images: ...target size imbalance and category semantic imbalance. To alleviate the impact of the above problems on object detection in unmanned aerial vehicle aerial images, this paper integrates the classic path aggregation network with the concept of gather-and-distribute mechanism, proposing a novel feature fusion architecture termed as gather-and-distribute path aggregation network(GD-PAN). GD-PAN leverages the advantages of both fusion approaches, resulting in a more thorough and comprehensive fusion of multi-scale feature maps, dramatically improving the refinement of the network for small target objects. Additionally, we introduce wider coordinate attention to optimize generation of coordinate offset and modulation scalar in deformable ConvNets version 2, which is applied to the basic network module of GD-PAN to enhance the feature extraction and fusion capability of the network for objects in different shapes and states. GD-PAN is a general improvement scheme that can be migrated to object detection algorithms based on the structure of path aggregation networks to improve their fusion ability on multi-scale features as well as small object detection performance. On the VisDrone dataset, the proposed method improves AP by 3.2%, mAP by 2.2%, and AP-small by 2.7% when used for real-time DETR, and when applied to YOLOv7 and YOLOv8, AP-small improves by 2% and 3.3%, respectively.
This paper investigates a class of generalized Cohen–Grossberg neural networks (CGNNs) with discontinuous activations and mixed delays. Based on the nonsmooth analysis theory, the drive-response ...concept, differential inclusions theory, we give several basic assumptions to gain the finite-time synchronization issue of CGNNs. Sufficient conditions are provided without the boundedness or monotonicity of discontinuous activation functions. Moreover, one can estimate the settling time’s upper bounds of the system. At last, two numerical examples and their simulations are given to further show the benefits of the obtained control approach.
Salinization is a severe threat to agriculture and the environment in many areas, and the same in Qaidam Basin, Qinghai Province, Northwestern China. Microorganisms have an important influence on ...regulating the biochemical cycles of ecosystems; however, systematic research exploring microbial diversity and interactions with saline-soil ecosystems’ environmental variables remains scarce. Thus, 16 S rRNA high-throughput sequencing was performed in this paper to characterize microbial diversity under different levels of salinized soils: non-salinized (NS, 2.25 g/L), moderately salinized (MS, 6.14 g/L) and highly salinized (HS, 9.82 g/L). The alpha diversity results showed that the HS soil was significantly different from the NS and MS soils. An analysis of similarity (ANOSIM) and a principal co-ordinates analysis (PCoA) indicated that NS and MS clustered closely while HS separated from the other two. Significant differences in microbial composition were observed at the taxonomic level. Proteobacteria (42.29–79.23 %) were the most abundant phyla in the studied soils. Gammaproteobacteria (52.49 and 66.61 %) had higher abundance in the MS and HS soils at the class level; Methylophaga and Pseudomonas were the predominant bacteria in the HS soil; and Azotobacter and Methylobacillus were abundant in the MS soil. Most genera belonging to Proteobacteria and Actinobacteria were detected via a linear discriminate analysis (LDA) effect size (LEfSe) analysis, which indicated that microbes with the ability to degrade organic matter and accomplish nutrient cycling can be well-adapted to salt conditions. Further analyses (redundancy analysis and Mantel test) showed that the microbial communities were mainly related to the soil salinity, electrical conductivity (EC1:5), total phosphorus (TP) and ammonia nitrogen (NH4+-N). Overall, the findings of the study can provide insights for better understanding the dominant indigenous microbes and their roles in biochemical cycles in different saline soils in the Qaidam Basin, Qinghai Province, China. The researches related to microbial community under typical poplar species should further clarify the mechanism of plant-microbial interaction and benefit for microbial utilization in salt soil remediation.
•The structural responses with respect to different salinity levels in Qaidam basin were investigated using 16 s rRNA high throughput sequencing method.•The alpha diversity showed significant difference in high saline soil compared with non-saline and moderate soils.•The microbial community structures were significantly differed along with the salinity levels in Qaidam basin.•Microbes with functions like polysaccharide degradation and strong metabolic capacity, survive better in saline soils.•The microbial community diversity and abundance were mainly correlated with soil salinity, EC1:5, TP and NH+4-N.
Abstract
To achieve sustainable development goals in Huangshui River Basin (HRB), strengthening adaptive water resources management under the dual impact of climate change (CC) and human ...interventions (HI) is of great significance. Multiple mathematical and statistical methods were employed to determine the runoff trend and breakpoint in HRB. The elasticity of CC and HI on the runoff decline and their contributions were quantitatively discerned based on the Budyko hypothesis, complementary method, and SWAT hydrological model. The results show that (1) the runoff showed a decreasing trend, with a runoff breakpoint in 1990; (2) the elasticity coefficients indicated a 1% increase in P, ET0, and n, leading to a 2.19% increase, a 1.19% decrease, and a 1.52% decrease in the runoff, respectively; (3) the Budyko framework determined the contribution of CC and HI to runoff decline in HRB to be 37.98–41.86% and 58.14–62.02%, respectively, and that estimated by SWAT hydrological model to be 38.72 and 61.28%, respectively; (4) HI were the primary factor for runoff decline in HRB, where direct anthropogenic disturbances such as water withdrawals and water conservancy project construction were the main drivers. The findings have important scientific significance for water resources planning and management in HRB.
Recently, Goji berry (Lycium barbarum L.) has been extensively cultivated to improve the fragile ecological environment and increase the income of residents in Qinghai Province, northwestern China. ...However, few studies have focused on the physiological responses of Goji berry under salt stress and alkali stress. Gas exchange, photosynthetic pigments, and chlorophyll fluorescence were evaluated in response to neutral (NaCl) and alkali (NaHCO
) salt stresses. Nine irrigation treatments were applied over 30 days and included 0(Control group), 50, 100, 200, and 300 mM NaCl and NaHCO
. The results showed that salt and alkali stress reduced all the indicators and that alkali stress was more harmful to Goji berry than salt stress under the same solution concentrations. The salt tolerance and alkali resistance thresholds were identified when the index value exceeded the 50% standard of the control group, and threshold values of 246.3 ± 2.9 mM and 108.4.7 ± 2.1 mM, respectively, were determined by regression analysis. These results were used to identify the optimal water content for Goji berry. The minimum soil water content to cultivate Goji berry should be 16.22% and 23.37% under mild and moderate salt stress soils, respectively, and 29.10% and 42.68% under mild and moderate alkali stress soil, respectively.
In the last several decades, microbial reduction of U(VI) to U(IV) has been applied as a method to remediate uranium contamination in situ. The U(VI) bioreduction kinetics and resulting U(IV) ...speciation are affected by various environmental factors, such as humic substances (HS) and Fe-bearing clay minerals. Previous studies have largely focused on their individual effects on U(VI) bioreduction. However, HS and Fe(III)-bearing clay minerals often co-exist at uranium contaminated sites, their joint effects may be different from the sum of their individual ones, due to either synergistic or antagonistic interactions between the two. In this work, we investigated the combined effects of HS and Fe(III)-bearing clay minerals (Fe-rich nontronite and Fe-poor montmorillonite) on U(VI) reduction by Shewanella putrefaciens and the resulting U(IV) speciation. HS alone exhibited an inhibitory effect on U(VI) bioreduction, likely because HS retained a fraction of electrons from microbial oxidation of lactate. The resulting U(IV) was in the form of aqueous U(IV)-HS complex. Clay minerals alone also inhibited U(VI) bioreduction because a fraction of reduced U(IV) was likely re-oxidized by structural Fe(III) and thus electrons were partially diverged from U(VI) to structural Fe(III). Bioreduced U(IV) was in a solid phase. However, in the presence of both HS and clay minerals, their combined effect of inhibition on U(VI) bioreduction was not a simple addition of the two individual ones. In the co-presence of clay minerals and a low concentration of HS (10 and 20 mg C/L), their combined inhibition effect on U(VI) bioreduction was stronger than that of HS but weaker than that of clays. The stronger inhibition than that of HS alone was due to electron diversion by clay minerals. The weaker inhibition than that of clays alone was because HS and/or Fe(III)-HS/Fe(II)-HS served as electron shuttles to accelerate the rate of Fe(III) reduction. These double shuttles decreased the ability of structural Fe(III) in clays to diverge electrons from U(VI) and thus partially negated the inhibitory effect of clay minerals. In the co-presence of clay minerals and a high concentration of HS (100 mg C/L), their combined effect on U(VI) bioreduction was initially similar to that in the low concentration of HS scenario. However, over extended time, clay minerals partially negated the inhibitory effect of HS, likely because clay minerals adsorbed a fraction of HS and thus lowered the ability of residual aqueous HS to retain electrons. Biogenic U(IV) was sequestered in solid in the presence of Fe-rich nontronite and HS but partially remained soluble in the presence of Fe-poor montmorillonite and HS. This study highlights the importance of the complex interaction between HS and Fe-bearing clays in bioreduction of U(VI) and speciation of the resulting U(IV).
Impervious surfaces are key indicators for urbanization monitoring and watershed degradation assessment over space and time. However, most empirical studies only extracted impervious surface from ...spatial, temporal or spectral perspectives, paying less attention to integrating multiple dimensions in acquiring continuous changes in impervious surfaces. In this study, we proposed a neighborhood-based spatio-temporal filter (NSTF) to obtain the continuous change information of impervious surfaces from multi-temporal Landsat images in the Qinhuai River Basin (QRB), Jiangsu, China from 1988–2017, based on the results from semi-automatic decision tree classification. Moreover, we used the expansion intensity index (EII) and the landscape extension index (LEI) to further characterize the spatio-temporal characteristics of impervious surfaces on different spatial scales. The preliminary results showed that the overall accuracies of the final classification were about 95%, with the kappa coefficients ranging between 0.9 and 0.96. The QRB underwent rapid urbanization with the percentage of the impervious surfaces increasing from 2.72% in 1988 to 25.6% in 2017. Since 2006, the center of urbanization expansion was shaped from the urban built-up areas of Nanjing and Jiangning to non-urban built-up areas of the Jiangning, Lishui, and Jurong districts. The edge expansion occupied 73% on average among the different landscape expansion types, greatly beyond outlying (12%) and infilling (15%). The window size in the NSTF has a direct impact on the subsequent analysis. Our research could provide decision-making references for future urban planning and development in the similar basins.
In order to improve the wear resistance of offshore drilling equipment, CoCrFeNiMn high-entropy alloy coatings were prepared by cold spraying (CS) and high-speed oxygen fuel spraying (HVOF), and the ...coatings were subjected to vacuum heat treatment at different temperatures (500 °C, 700 °C and 900 °C). The friction and wear experiments of the coatings before and after vacuum heat treatment were carried out in simulated seawater drilling fluid. The results show that CoCrFeNiMn high-entropy alloy coatings prepared by CS and HVOF have dense structure and bond well with the substrate. After vacuum heat treatment, the main peaks of all oriented FCC phases are broadened and the peak strength is obviously enhanced. The two types of coatings achieve maximum hardness after vacuum heat treatment at 500 °C; the Vickers microhardness of CS-500 °C and HVOF-500 °C are 487.6 and 352.4 HV
, respectively. The wear rates of the two coatings at room temperature are very close. CS and HVOF coatings both have the lowest wear rate after vacuum heat treatment at 500 °C. The CS-500 °C coating has the lowest wear rate of 0.2152 mm
m
N
, about 4/5 (0.2651 mm
m
N
) of the HVOF-500 °C coating. The wear rates and wear amounts of the two coatings heat-treated at 700 °C and 900 °C decrease due to the decrease in microhardness. The wear mechanisms of the coatings before and after vacuum heat treatment are adhesive wear, abrasive wear, fatigue wear and oxidation wear.
Sarcopenic obesity (SO) in nursing home residents is rarely studied. We aimed to evaluate and compare the prevalence and consistency of different SO diagnostic methods and to investigate which ...criterion demonstrated a stronger association with instrumental activities of daily living (IADL) disability.
We consecutively recruited older adults aged ≥ 60 years, residing in 15 nursing homes in Zigong City, China. Sarcopenia obesity was defined according to the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity criteria (SO
), recommending skeletal muscle mass (SMM) adjusted by body weight (SMM/W) to identify low muscle mass. Further, we adapted ESPEN criteria (SO
) by employing SMM adjusted by body mass index (SMM/BMI).
We included 832 participants (median age 73.0 years, 296 women). The prevalence of SO
and SO
was 43.5% and 45.3%, respectively. SO
showed good consistency with SO
(Cohen's kappa = 0.759). More than one-third of participants in the normal weight group were diagnosed with SO
or SO
. Even within the underweight group, the prevalence of SO
and SO
was 8.9% and 22.2%, respectively. Participants with IADL disability had significantly lower SMM/W and SMM/BMI, but higher fat mass percentage of body weight (FM%) than participants without IADL disability. After full adjustment for potential confounders, SO
(OR 1.68, 95% CI 1.21 to 2.32), but not SO
(OR 1.28, 95% CI 0.93 to 1.75), remained significantly associated with IADL disability.
Both SO
and SO
showed a high prevalence among nursing home residents, even among individuals with underweight or normal weight. While SO
had a good consistency with SO
, only SO
was independently associated with IADL disability. Screening and diagnosis of SO should be conducted in nursing home residents irrespective of BMI.
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