Search

[Objective] The aim of this study is to examine the regulatory effects and thresholds of different land uses on runoff variations in the middle reaches of the Yellow River, which is crucial for flood control and the high-quality development of the watershed. [Methods] Focusing specifically on the Dali River Basin, the characteristics of land use changes over the past 20 years were analyzed, and the impact of these changes on the annual distribution of runoff was quantitatively assessed by using a monthly scale SWAT model of the basin. Four extreme land use scenarios were set to study the impact of different land use types on flood season runoff. Additionally, 12 different land use coverage scenarios were used to determine the critical coverage of land use that affected watershed runoff. [Results] The predominant land use modes in the Dali River Basin included arable land, grassland, and forest land. Grassland and forestland exhibited an inhibitory effect on runoff, while arable land promoted runoff. The impact coefficients for these land use types were-0.1252,-0.130 1, and 0.122 3, respectively. Land use had a certain regulatory effect on the annual distribution of runoff. However, this effect was not significant when land use changes were small. [Conclusion] Notably, land use coverage demonstrates a significant marginal effect, with a lower critical value of approximately 5% for grasslands and an upper critical value of 95%, as well as an upper critical value of 91% for forests. These findings can provide valuable insights for soil and water conservation efforts, flood control initiatives, and the high-quality development of the watershed. [ABSTRACT FROM AUTHOR]

Based on the field trips, this paper conducts a comparative study on the competitiveness of major industries in the planting industry in Zhenyuan County. The paper builds an index system for industrial competitiveness evaluation through Analytic Hierarchy Process. An overall score and ranking of the competitiveness of the planting industry are produced based on Delphi method assignment and matrix calculation, which provides a strategy for the agricultural sector to select leading industries that can be guided and supported in the future, as well as puts forward suggestions for the development of local agricultural industries. [ABSTRACT FROM AUTHOR]

The construction of high-standard warping dam is one of the main measures to achieve the national strategic goals of ecological protection and high-quality development of the Yellow River Basin, which will play a greater role in promoting the high-quality development of water and soil conservation and regional economic and social development. Based on the goals and requirements of high-quality warping dam construction, this paper analyzed the historical process of warping dam construction and technical standard development in the Yellow River Basin, discussed the definition and connotation of high-standard warping dam, put forward scientific issues and key technologies that need to be studied, and looked forward to the development prospect of high-standard warping dam. The warping dam in the Yellow River Basin has gone through a development process of more than 450 years in six stages, and the high-standard warping dam marks that the construction of warping dam has entered into a new period from “quantity”development changed to “quality”promotisn. The technical standards of warping dams have undergone a development process from the formation in the mid-80s of the 20th century to continuous improvement and revision along with the level of science and technology and practical experience in different periods. Compared with ordinary warping dams, high-standard warping dams have special essential characteristics, value and richer connotation and extension. The status and driving mechanism of high-standard warping dams in the comprehensive benefit chain and the technical standards of high-standard warping dam construction are topics that need to be studied in the future. The construction of high-standard warping dams will surely promote the high-quality development of soil and water conservation, and play a greater role in the coordinated development of multiple elements such as regional ecological governance, derivative economy, social culture, and landscape pattern. [ABSTRACT FROM AUTHOR]

Rainstorm has been one of the key factors causing runoff and soil erosion in the Yellow River Basin of China. The check dam can serve as one of the most important engineering measures for soil and water conservation during soil erosion control in the Loess Plateau. However, the check damn has posed a great impact on the formation, evolution, and development of the rainstorm runoff process via the changing runoff, erosion dynamics, and energy distribution in the watershed. Therefore, it is crucial to reveal the various elements nexus in the erosion system of the watershed, in order to explore the disaster mechanism of rainstorm runoff under the action of soil and water conservation measures. This study aims to quantitatively reveal the influence of the check dam configuration on the formation and rainstorm runoff evolution in small watersheds of loess hilly regions. An indoor experiment of artificial simulated rainfall was carried out to analyze the hydrodynamics and erosion dynamic characteristics of runoff at different sections in small watersheds with the different measures (no dam, single, and double dam) and the rainfall intensity as 60 mm/h, according to scale relationship. The results showed that: 1) The sediment concentration of runoff increased significantly, as the time and erosion increased the most in the case of a no-check dam. The maximum increase of erosion (runoff) was more than 114.60 cm³/s (only 70.11 cm³/s) in the case of no (double) dam. The sediment concentration values under the No. 1 single dam, No. 2 single and double dam were reduced by 0.14, 0.14, and 0.19 g/cm³, respectively, compared with that without the dam. 2) The check dams posed a significant impact on the evolution process of rainstorms and runoff in small watersheds. The double dam was the most effective to restrain the increase of velocity, while the limited control effect, compared with the single dam. The check dam had also a great influence on the runoff flow state, where the increasing resistance coefficient determined the runoff flow and sediment transport capacity. There was a time-delayed runoff from the laminar to a turbulent state, which increased the stability of flow state change. The runoff state started to change in 10-15 min without the dam, but without change in the check dam until 50 min later. 3) The check dam reduced the runoff power and runoff erosion power, further delaying the growth trend of runoff erosion power. The runoff power under the no-dam scenario was 1.42-2.45 (1.59-2.64) times that under the No.1 (double) dam scenario. More importantly, the flow pattern changed from the turbulent to laminar slow flow, where the Reynolds number decreased 12.04%-85.85% after the construction of the check dam. 4) The runoff process depended mainly on the runoff power, Reynolds number, runoff erosion power, and average velocity in small watersheds. The dominant parameters were ranked in the descending order of the runoff power, Reynolds number, runoff erosion power, and average velocity. The erosion dynamic parameters also posed a much greater impact on the evolution of runoff than the hydrodynamic force parameters. Consequently, the runoff power and Reynolds number can be expected to serve as the dynamic factors for the erosion sediment yield under different siltation dam configurations. The findings can offer practical implications for the pregnant environment and the disaster mechanism of rainstorms and runoff in the basin. A theoretical basis can also be used to evaluate the effect of soil and water conservation engineering measures on the regulation of the runoff process. [ABSTRACT FROM AUTHOR]

Complex soil erosion is an erosion phenomenon that occurs under the interaction or coupling of two or more erosive forces, and is one of the most difficult ecological problems to be managed. In recent years, remarkable progress has been made in the mechanism of complex erosion, the effect of complex erosion on soil degradation, and the simulation technology of multi-dynamic erosion interaction. Based on previous research, this paper systematically summarizes the research progress of the types and characteristics, mechanism and research methods of complex erosion. The main problems in the research are analyzed, and some key scientific problems to be solved in the future research on the law of complex erosion and the method of simulation test are put forward. Due to the obvious spatiotemporal heterogeneity and the complexity driven by multi dynamics in complex erosion, the existing research results are still quite different, and the dynamic mechanism of the occurrence and development of complex erosion is still unknown. The research on theory and method of complex erosion simulation and quantitative assessment is still very weak. In particular, there is a lack of effective test key technology to reveal the multi power driving relationship. At present, the problems in the study of complex erosion mainly include: 1) The multi-dynamic interaction relationship in complex erosion is not studied as a complete dynamic system; 2) The spatial-temporal variation relationship between complex erosion process and environmental factors is not clear enough; 3) It is still a key problem to quantitatively identify the contribution rate of each driving factor in the process of complex erosion; 4) The quantitative research on the coupling and superposition of multi dynamic factors in the process of complex erosion is not enough. In the future, the dynamic mechanism of the occurrence and development of complex erosion and the simulation of multi dynamic decomposition will become the key research direction. Therefore, it is necessary to clarify the complex erosion model under multi dynamic interaction, clarify the feedback mechanism of vegetation pattern on complex erosion, reveal the coupling mechanism of ecosystem degradation and complex erosion under multi dynamic stress, establish the identification method of the coupling relationship between multi dynamic complex erosion and sediment yield, and break through the theory and technology of complex erosion simulation. This will promote the development of complex erosion research from qualitative to quantitative, from process to mechanism, and will greatly enrich the research content of soil erosion dynamics, ecology and other related disciplines. We should focus on the following research directions: the simulation technology of rainfall-wind tunnel-freeze-thaw multi-dynamic alternating cycle test based on multi-source data fusion, quantitative evaluation technique and method for driving factor in compound erosion system, identification and quantification of sediment yield process under different coupling conditions of multi-dynamics in order to provide reference for related research. [ABSTRACT FROM AUTHOR]

In order to provide scientific and technological support for the implementation of major national strategies for ecological protection and high-quality development and rural revitalization in the Yellow River Basin, this paper systematically summarized the research results, key technologies and typical models of the coordinated development of ecological governance and ecological economy in the Yellow River Basin over the years, analyzed the current existing and outstanding issues, and put forward corresponding countermeasures and suggestions. Over the years, various regions in the Yellow River Basin have explored a variety of coordinated development models of ecological governance and ecological economy for serious soil erosion. It includes the comprehensive ecological and economic management model with high adaptability of soil and water conservation-geomorphology-ecological economy, the ecological agriculture economic model of soil and water conservation, the integrated development model of soil and water conservation and ecological economy in wind-sand area, the coordinated development model of ecological management and derivative industries in Pisha sandstone area, the virtuous cycle model of rural energy ecology in semi-arid areas, and the governance model of ecological and economic belt of soil and water conservation in the Loess Plateau. At present, the existing outstanding issues include the concept of coordinated development of ecological governance and ecological economy is weak, the synergy between the two is not high, the space for coupling and coordination is unbalanced, and the development model has a single structure and low scale efficiency. The suggestions: To innovate the theory and key technologies of coordinated development of ecological governance and ecological economy; To establish a diversified investment mechanism, create a new model of coordinated development of ecological governance and economy and its production and industrial system with the goal of high-quality development, and explore the promotion mechanism and model of “full trust and full chain”; To build an appropriate technical system, industrial system, management system and talent support system; To establish a pilot demonstration county for the coordinated development of ecological governance and ecological economy, lead and optimize the coordinated development of regional modern ecological governance and economy. [ABSTRACT FROM AUTHOR]

The reaction rates of a bituminous coal (Inner Mongolia) steam gasification with CaO additive had been studied with a pressurized fix-bed reactor through gas products analysis. The results show that CaO additive has a sufficient effect on char steam gasification rate,and the promotion effect of CaO on char steam gasification has a positive correlation with the mixing extent between CaO and char. Compared with non-CaO gasification, the steam gasification rate of char/CaO mixture which is the product of coal/CaO co-pyrolysis increases by 182. 34%. In addition,the steam gasification rate of the mixture of CaO and char that made of coal individual pyrolysis increases by 21. 13% . The degree of Ca2+ dispersion is the main factor which impacts char steam gasification rate. Furthermore, the reaction rate of char steam gasification with CaO additive has a positive correlation with Ca/C under the condition of Ca/C =Sl .0, while there would be a decrease in char/CaO steam gasification rate when Ca/C increases to 1.2, compared with the condition of Ca/C ≤ 1. 0. Temperature plays a sufficient role on char/CaO steam gasification rate. When temperature increases from 650 °C to 750 ℃ ,the reaction rate of char/CaO steam gasification increases by 594. 67% . When steam partial pressure increases from 0. 35 MPa to 0. 50 MPa and 0. 65 MPa,the char/CaO steam gasification rates increases by 95. 86% and 204. 14% Respectively. [ABSTRACT FROM AUTHOR]

Objective: Macrophage is a kind of immune cells with the ability of inflammatory chemotaxis. In recent years, macrophage membrane-camouflaged nanoparticle delivery system has attracted wide attention of researchers. Herein, a new method for macrophage membrane to camouflage nanoparticle-uptake-extrusion method is developed, and then we characterize the nanoparticles prepared by this method, and investigate the uptake of nanoparticles in different cells. Methods (s): DMSN nanoparticles loaded with doxorubicin were prepared by sol-gel method, and then DMSN was phagocytized by RAW 264.7 macrophages. Finally, macrophages were continuously extruded to prepare DMSN@CM nanoparticles. The particle size and zeta potential of DMSN@CM were measured by nanoparticle size analyzer. The morphology of nanoparticles was observed by transmission electron microscope. Polyacrylamide gel electrophoresis was used to verify the successful camouflage of cell membrane. Then the uptake of DMSN@CM in different cells was investigated by laser confocal microscope and flow cytometry. Results (s): DMSN and DMSN@CM nanoparticles were successfully prepared. The size of DMSN was 116.7±3.2 nm, and its zeta potential was -29.5±1.3 mV; The size of MSN@CM was 128.0±9.3 nm, and its zeta potential was -26.7±1.2 mV. TEM and SDS-PAGE jointly verified the successful coating of cell membrane. Cell uptake assay showed that the camouflage of macrophage membrane could inhibit the uptake of DMSN@CM in RAW 264.7 cells, and promote the uptake of DMSN@CM in MDA-MB-231 cells. Conclusion (s): Thus, we provide a simple and efficient method for macrophage membrane to camouflage nanoparticles-uptake-extrusion method, and successful constructed DMSN@CM nanoparticles based on this method. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of open source software bug localization, this paper proposed an open source soft. ware bug localization method based on twice propagation algorithm (TPA). It combined the restart random walk with the label propagation algorithm based on the information retrieval method. The specific location of the bug is analyzed from the three aspects: the call relationship, module risk and historical bug report of each module in the open source software. The bug localization is divided into two parts: risk propagation and label propagation. Through the similarity and calling relationship between the software modules, combined with the history of modified reports, it evaluated the module' s risk. It constructed the bug label through the modified bug reports, and propagated the software label from it. In the Eclipse 3.1 bug report data set, the top-N rank and MRR indicators are higher than the similar bug location methods. Experiments show that the TPA method has higher accuracy. [ABSTRACT FROM AUTHOR]

The erosion mechanism ofPisha sandstone has been the basic key problem in the improvement of local ecological environment in North China. In order to better understand the process of Pisha sandstone compound erosion and revelation the relationship between erosion alternate and coupling, study the mechanism of compound erosion and vegetation degradation, the main present research of Pisha sandstone erosion mechanism was well rounded summarized, including the erosion type and mechanism, distribution characteristics of Pisha sandstone erosion, erosion mechanism of Pishan sandstone et al. It discussed the current research, some key scientific issues of the erosion mechanism of Pisha sandstone were pointed out and some significance projects of Pisha sandstone erosion were suggested, including spatio temporal differentiation of Pisha sandstone compound erosion based on multi power, the relationship between compound erosion and vegetation degradation, the break mechanism of Pisha sandstone three-element structure under the water rock interaction and the observation method of the compound erosion experiment. The conclusion could be useful for the correlation research in the future. [ABSTRACT FROM AUTHOR]

Nucleic acid therapy has received more and more attention in recent years, but nucleic acid drugs are easily cleared quickly, easily degraded by nucleases, non-specific biodistribution and not easily taken up by cells, making it difficult to exert effects in the body. This article provides glutathione (GSH) responsive release nanoparticles capable of effective nucleic acid drug delivery. Methods Use hexadecyltrimethylammonium chloride (CTAC) to prepare mesoporous silicon nanoparticles, modify and activate sulfhydryl groups on the surface of mesoporous silicon nanoparticles, and make them react with sulfhydryl modified polypropylene imine and polyethylene glycol to form mesoporous silicon nanoparticles with GSH response. The particles are loaded with nucleic acid by electrostatic adsorption. The Malvern particle size analyzer measures the surface potential and particle size, and observes the morphology of the nanoparticles with a transmission electron microscope. Nucleic acid electrophoresis is used to detect the nucleic acid loading efficiency, the GSH response to the release of PEI is detected in vitro, and the cell uptake and lysosome escape are observed by confocal microscope. The nanoparticles with GSH response were successfully constructed, with a particle size of 76.44±1.68 nm and a surface potential of 33.93± 0.59 mV. The nanoparticles were observed to be round and porous particles through transmission electron microscopy. The agarose nucleic acid loading experiment demonstrated when the ratio of nitrogen to phosphorus is greater than 20, nucleic acid can be loaded efficiently. Confocal microscopy showed that the nanoparticles could be successfully taken up by MDA-MB-231 breast cancer cells. In the lysosomal escape experiment, it was observed that the fluorescence of Cy5-siRNA separated from the fluorescence of the lysosome after 3 h entering the cell, which proved the established nanoparticles successful escaped from the lysosome. The mesoporous silicon nanoparticles with GSH response have been successfully constructed, which can be effectively used for nucleic acid delivery. [ABSTRACT FROM AUTHOR]

In the middle reaches of the Yellow River Basin, water-soil disasters are widely distributed with many types and strong suddenness. Moreover, these disasters are often chain-generated and have serious consequences, which are harmful to the safety of ecological environment and human settlement security of the Yellow River Basin. Therefore, it is necessary to clarify the mutual feedback mechanism between water-soil disasters and ecological environment, and strength the research on the mechanism and chain effect of water-soil disasters in the middle reaches of the Yellow River Basin. In this paper, based on the problem of water-soil disasters, we firstly reviewed the research status and development trends of the laws of mountain torrents, the occurrence mechanism of loess collapse, landslides and debris flow, the chain-effect of water-soil disasters, and the mutual feedback effect of water-soil disasters and ecological environment. Then we discussed the research trends and challenges of water-soil disasters in the middle reaches of the Yellow River Basin. Lastly we analyzed the key scientific issues to be solved in the research of water-soil disasters, and put forward relevant research suggestions based on the idea of earth system science. The main research directions of water-soil disasters are as follows: the laws of mountain torrents under the action of extreme rainfall, the mechanism of water-soil disasters under the coupling effect of geomorphology and climate, the amplification and reduction effects of chaineffect of water-soil disasters considering ecological impact, and the mutual feedback effect of water-soil disasters and ecological environment. The key scientific issues to be solved urgently are to reveal the response relationship between geological, geomorphic and climatic processes and the water-soil disasters from the perspective of coupled linkage, to reveal the dynamic process and disaster effect evaluation of soil-water disasters chain from the perspective of disaster effect, to establish the theory of mutual feedback between water-soil disasters and ecological environment from the perspective of geological security and ecological security, and finally to propose the disaster reduction technology based on the feedback effect evaluation of water-soil disasters and ecological environment. The research suggestions are that : based on the theory of earth system science, we should emphasize the interdisciplinary integration, and clarify the regional model, dynamic mechanism, disaster chain and feedback effect of ecological environment and water-soil disasters in the middle reaches of the Yellow River from the spatial scale of land, region and river. We should establish a comprehensive risk assessment model, and prevention-control theory of water-soil disasters in the middle reaches of the Yellow River from the perspective of human geography relations coordination theory. [ABSTRACT FROM AUTHOR]

Soil erosion and sediment transport in Losses Plateau region are crucial for sustainable development of the local region and downstream of Yellow river due to the harmful sedimentation in the plain area. This study was to investigate the sediment transport capacity and flow-sediment relationship in different topographical units of different scales in loess region to explore the countermeasures for solving the sediment-related environmental issues. The Peijiamao watershed in losses region was selected as prototype for observation, including the embedded whole slope runoff plot (0.25 hm2) and 3 hydrological stations that were first branch of Qiaogou (subwatershed of Qiaogou watershed), Qiaogou watershed (subwatershed of Peijiamao watershed), and Peijiamao watershed (3930 hm2) with increasing scales, acting as 4 different topographical units. The rainfall, runoff and sediment contents data at these sites were recorded and collected from 1986 to 2008. Results showed that during the observation period the runoff depth and the sediment transport modulus at the annual timescales of the slope scale were more than that of the watershed scale, probably due to the well-known gravitational erosion occurring on the steeper slopes at slope scale in this region. When the spatial scale was up to the watershed scale, at the annual timescale the runoff depth increased with the spatial scale, but the sediment transport modulus decreased with spatial scale. However, at the inter-event timescale the maximum value of the runoff depth and the sediment transport modulus may occur at the different topographical units influenced by the rainfall process, rainfall duration, rainfall spatial distribution, the antecedent soil moisture content and other factors. Totally, 67.74% of the runoff peaks occurred at whole slope runoff plot and 29.03% at entire Peijiamao watershed. However, 38.71% of sediment transport modulus occurred at whole slope runoff plot and 48.39% occurred at entire Peijiamao watershed. With the increasing in spatial scale, the sediment transport capacity decreased dramatically. The sediment concentration carried by unit flow power of the whole slope runoff plot, the first-branch of Qiaogou and the Qiaogou was 186, 77 and 58 times that of entire Peijiamao watershed, respectively. It was further confirmed that slope scale triggered tremendous intensity of soil erosion, and the probability of hyper-concentration flow decreased when spatial scale increased. The gentler slope in the larger watersheds from first branch of Qiaogou to the whole Peijiamao watershed and more interception by the flattened terraces might lower sediment transport capacity in this region. Furthermore, the probability of hyper-concentrated flow was closely related to the ratios of width to depth of the different gully. Result showed that the smaller the ratio of width to depth the bigger the probability of hyper-concentrated flow. In this study, the ratios of width to depth of the watershed gullies were 8.15, 15.86 and 38.09, respectively at the 3 watershed scales from first branch of Qiaogou to the whole Peijiamao watershed and the gully gradient decreased with spatial scales from 4.97% at subwatershed of Qiaogou watershed to 1.51% at Peijiamao wathershed. The runoff-sediment transport modulus relationship of different topographical units was in linear function, suggesting that runoff volume was the controlling factor of sediment transport. And with the increase in spatial scale, the runoff-sediment transport modulus relationship was more significant from 0.71 at whole slope runoff plot to 0.99 (for the decisive factor) at entire Peijiamao watershed scale. It also showed that curve slope decreased with increase in watershed area, with highest slope of 1.10×106 at whole slope runoff plot and 1210 at entire Peijiamao watershed indicating that the relationship between runoff and sediment was more complex in the slope scale. The results can provide valuble inforamtion for exploring the spatial scale effects and scale transformation of soil erosion in Losses Plateau region. [ABSTRACT FROM AUTHOR]