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Northeast China played an irreplaceable role in population migrations and cultural exchanges in East Asia during the Paleolithic. This paper collected 182 archaeological sites to analyse the characteristics of spatial-temporal variations of Paleolithic human activities in Northeast China, and explored the driving mechanisms behind these variations in combination with the paleoenvironmental and archaeological studies. During the Lower Paleolithic, constrained by the relatively cold-dry climate and blocked by the Songnen paleo-lake basin, the population was sparse and distributed only near 40° N at the southern end of Northeast China. Upon entering the Middle Paleolithic, as humans developed greater tolerance to cold climates and adopted more sophisticated survival strategies with the application of small lithic tools, their numbers increased and geographical distribution expanded northward to 45° N at the central region of Northeast China. The Upper Paleolithic saw a considerable increase in population and expansion across almost all of Northeast China except for the eastern Inner Mongolia Plateau. We speculated that 50 ka and 30 ka BP were two key points, both of which may be associated with a significant increase in the frequency of migrations and communications among humans, and the widespread popularity of highly mobile microblade technology, respectively. In addition, the environmental analysis of archaeological sites revealed a continuous spread of Paleolithic humans to areas with higher elevations, steeper slopes, and lower temperatures. Meanwhile, they were becoming less reliant on water resources and were more widely conducting activities in open-air areas, showing that the environmental adaptability had been continuously improving over time. This study can provide a reference for the reconstruction of the migration history of early humans in East Asia, and is also of great significance for a comprehensive understanding of the evolutionary process of early human-environment interactions. [ABSTRACT FROM AUTHOR]

The unavoidable wind power prediction error poses a challenge for wind power to participate in day-ahead scheduling plan. This paper proposes a two-stage correction method considering NWP wind speed and power correction. Firstly, this paper fully considers the historical similarity of NWP wind speed, and adopts the improved clustering distance for segment matching and wind speed correction based on the extracted most relevant trend component, which enhances the utilization of NWP information and avoids the randomness and uncertainty of the intelligent correction method, and gram angular field (GAF) and stacked autoencoder (SAE) are used for feature extraction and conditional variational autoencoder (CVA) is used to generate specific samples to ensure the adequacy of the clustering process. Secondly, considering the historical similarity of error of predicted power, the power is further corrected based on the proposed weighted double-constraint to realize the secondary calibration. The Proposed method is applied to several wind farms in China to verify its effectiveness. The results show that the proposed method reduces the N RMSE by 3.82 % and N MAE by 3.40 % compared with direct prediction in the wind farms in western Inner Mongolia, which is important for promoting wind power consumption and maintaining the safe and stable operation of the power system. • Propose a method to extract the most relevant trend component form wind speed. • Propose a novel method for wind speed correction and power calibration. • Propose a sample condition generation method based on GAF and CVA. • Propose an improved clustering distance into the wind speed correction process. [ABSTRACT FROM AUTHOR]

• This paper analyzes whether the financial support for grassland ecological protection and restoration has improved the vegetation coverage of grassland. • There is a nonlinear relationship between financial support for ecological restoration and grassland vegetation coverage. • Different fiscal expenditure structure has a heterogeneous response. • The degree of fiscal decentralization has a significant positive regulatory effect on the ecological benefits. Grassland ecological restoration is an important cornerstone to maintain the sustainable development of grassland ecosystem. One of the goals of financial support for grassland ecological protection and restoration is whether the ecological benefits of grassland are fully realized, and grassland vegetation coverage is the main index to measure the ecological benefits. This paper aims to analyze whether the financial support for grassland ecological protection and restoration has improved the vegetation coverage of grassland. and then verify whether there is room for improvement in the fiscal effect of grassland ecological protection and restoration? Based on the panel data of 54 animal husbandry and semi-agricultural and semi-animal husbandry counties in Inner Mongolia Autonomous Region of China, this paper adopts a bidirectional fixed effect model and cross-fixed effect model to introduce natural factors affecting grassland vegetation coverage into the model and systematically examines the financial effects of ecological benefits of financial support for grassland ecological protection and restoration. The main findings are as follows: (1) there is a nonlinear relationship between financial support for grassland ecological protection and restoration and grassland vegetation coverage when natural factors are taken into account in the model. (2) different fiscal expenditure structure has a heterogeneous response to the impact of grassland ecological protection and restoration on ecological benefits. (3) the degree of fiscal decentralization and the relative performance of the government have a significant positive moderating effect on the ecological benefits of fiscal support for grassland ecological protection and restoration. [ABSTRACT FROM AUTHOR]

Uranium mainly comes from ISL of sandstone-type uranium deposits in China. The change of porosity and permeability caused by blockage of ore-bearing strata is one of the most serious problems in acid ISL of uranium. In this paper, the groundwater tracer test was carried out before and 1 year after ISL to explore the pore and permeability evolution characteristics of the ore-bearing layer during ISL. The test results showed that the leaching solution migrated along two seepage channels and the water-bearing medium was isotropic. After 1 year of ISL, the flow rate of the leaching solution decreased obviously. However, the flow rate of the leaching solution in slower channel decreased more than that in the faster channel in all directions, which was caused by the more adequate chemical reactions between the leaching solution and the minerals of the ore-bearing layer and the more corresponding precipitation in the slower channel. In addition, the flow rate along the direction of groundwater flow decreased less than that in the direction of vertical groundwater flow. This was closely related to the transformation of aquifer medium by hydrodynamic field. Initial stage of ISL, the occurrence of plugging is closely related to the precipitation-dissolution process of iron and aluminum minerals under the change of pH, which is accompanied by the continuous precipitation of gypsum. • Groundwater tracing tests before and after in-situ leaching were carried out. • The pore and permeability evolution characteristics of the ore-bearing layer was analyzed. • The plugging of pores in different directions was clarified. • The relationship between dissolution-precipitation process and permeability was discussed. [ABSTRACT FROM AUTHOR]

Grain size is commonly used as a proxy to reconstruct past lake hydrology; however, published research rarely links grain size with modern processes, and uncertainties exist for interpretation. In this paper, we decompose the grain size frequency distributions (GSFD) for 196 lake surface sediments from 61 lakes and 9 reservoirs across the Inner Mongolia Plateau and adjacent areas and divide them into five GSFD components. We statistically analyze the relationship between the GSFD components and influencing variables to determine the taphonomic dynamics and their environmental implications. Within individual lakes, we found that GSFD component 4 (74.00–209.30 μm) and GSFD component 5 (209.30–592.00 μm) dominate near the lake margin and reduce toward the lake center in proportions. By contrast, GSFD component 2 (2.75–15.56 μm) increases toward the lake center. Therefore, the proportions of GSFD component 2, 4, and 5 reflect the relative distance to the lakeshore and allow inferences about lake area changes. We apply this large modern dataset to a sediment core obtained from Lake Wulanhushao (WLHS) on the Inner Mongolia Plateau and link the lake surface sediment-based GSFD components to BEMMA end-members of grain size records to define their environmental implications over the last 18.59 cal. kyrs BP. We found that the Lake WLHS has responded to the orbital and suborbital climate changes since the last deglaciation. Specifically, maximum lake transgression prevailed during the early to middle Holocene (11.70–7.10 cal. kyr BP), medium lake transgression dominated during 17.05–15.80 cal. kyr BP, and weak transgression developed during 14.60–12.90 cal. kyr BP. Maximum lake regressions prevailed before 17.05 cal. kyr BP, during 15.80–14.60 cal. kyr BP and 12.90–11.70 cal. kyr BP. Our reconstructed early Holocene maximum lake area is consistent with regional abiotic proxy-based moisture records, but contrasts with the regional biotic proxy-based moisture records, which reconstruct increasing moisture conditions. Our new method to determine lake area changes will provide valuable data to understand the climate dynamics of northern China. • We numerically revealed the environmental implications of grain size components of lake surface sediment. • Linking lake surface sediment grain size component to core end members provide basis for interpretations. • Maximum lake transgression prevailed during the early Holocene in northern China. • Abiotic proxies-based early Holocene lake transgression is distinct with biotic proxies' reconstructions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Predict the evolution of land use and landscape ecological risk. • Couple landscape ecological risk and ecological security network. • Construct an ecological security network for multiple future development scenarios. • Explore sustainable development scenario for Northeast China. • Make recommendations for ecological security network optimization. The expansion of human activities has significantly increased ecological risks, which threaten the security of ecosystems. This paper takes Northeast China, a national typical ecological barrier region, as a case study to explore the evolution of the ecological environment under various future development scenarios. Considering the complexity of ecological assessments, a comprehensive approach integrating various methods is employed. This includes the Patch-based Land Use Simulation (PLUS) model, Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, a landscape ecological risk assessment index system, the Space Minimum Cumulative Resistance (MCR) model, among others. These methods are used to dynamically assess changes in land use, landscape ecological risk (LER), and the layout of ecological networks. An integrated framework is proposed for identifying, constructing, and optimizing the ecological security network (ESN). The results show that the LER in Northeast China presents a "high in the middle, low around" distribution characteristic. High risk areas are mainly distributed in water bodies and construction lands with high landscape fragmentation and isolation, while low risk areas are primarily in the Northeast forest belt and Inner Mongolia grassland areas with lower landscape vulnerability and separation. From 2000 to 2020, the LER in the Northeast China has increased, primarily manifested in the Greater and Lesser Khingan Range areas in the northern part of the study region. Forecast results indicate significant differences in the evolution of LERs and the layout of the ESN under different socio-economic development scenarios. Under the ecological protection (EP) scenario, the average LER in Northeast China is 0.2215. The area of ecological source lands is 302,405.56 km2, the length of ecological corridors is 179,024.71 km, with 339 ecological nodes and 410 ecological breakpoints identified. Compared with the natural development (ND) and urban construction (UC) scenarios, the EP scenario in Northeast China shows the lowest LER and the most ideal layout of the ESN. This study provides a reference for future land resource optimization and ecological restoration in Northeast China. [ABSTRACT FROM AUTHOR]