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Experimental determination of sediment transport capacity of rill flow over sandified loess slope

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International Soil and Water Conservation Research 2023年第2期11卷 301-310页

作者： Ren Feng Jiacun Chen Zhenyue Xie Dingqiang Li Zaijian Yuan National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and ManagementInstitute of Eco-environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou510650China Meizhou International Institute of Soil and Water Conservation Meizhou514000China

Rill erosion is affected by the sand particle content in soil,especially in the wind and water erosion transition region of the Loess *** sediment transport capacity(STC)is a key parameter in rill erosion research,assessing the impact of aeolian sand intrusion on the STC of rill flow is of importance for a better understanding of rill *** study aimed to assess the effect of aeolian sand intrusion on the STC on sandified loess slopes,with typical slopes and flow discharges,using a flume system which consisting of a sediment-feeding and a sediment-supply/settlement *** sediment feeding flume was jointed by 10°higher than that of the sediment measurement flume *** flow discharges(2,4,and 8 L min^(-1))and four slope gradients(5°,10°,15°,and 25°)were used to represent the natural hydrological conditions under three intrusion rates(SIR)of aeolian sands(10%,20%,and 50%).The results show that STC increased with slope gradient and flow discharge,and the relationship between the STC and the SIR was significantly affected by the slope gradient;the STCs decreased with the SIR on a slope of 5°but increased with the SIR on steep slopes of 15°-25°,implying a significant impact of slope gradient on the relationship between SIR and *** SIR of 50%resulted in the highest sediment concentration nearly 1200 kg m^(-3)on slopes of 25°.On sandified loess slopes of 10%,20%,and 50%SIR,the STC were about 30%,46%,and 57%higher than on loess slopes,indicating an increased erosion rate by sand particle intrusion into loess *** results highlight the impact of sand intrusion on STC of rill flow and provide deeper insights into the soil loss process on the sandified loess slope.

关键词： Sand intrusion Loess soil Rill flow transport capacity

Calculation of railway transport capacity in an emergency based on Markov process

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Journal of Beijing Institute of Technology 2012年第1期21卷 77-80页

作者：孟学雷贾利民秦勇徐杰王莉 School of Traffic and transportation Lanzhou Jiaotong University State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University

A method is proposed to calculate the railway transport capacity in an emergency to support the dispatching work of control centers. The effect of an emergency on section transport capacity is analyzed and the basic method to calculate the transport capacity is presented. The results show that the situation-changing process in emergency is actually a Markov process. The calculation rule is presented based on division of the time segment during which the emergency lasts. The algorithm is designed to calculate the transport capacity of each time segment. The pessimistic strategy and the fuzzy strategy are proposed to determine the computing value of the transport capacity of each time segment, to satisfy the calculating requirements in different occasions. Our study shows that the method is reasonable and practical and the method can be embedded in the train dispatching system to support the operation work in an emergency.

关键词： transport capacity calculation emergency Markov process

Numerical study of geyser events in rainstorm systems at different scales

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Water Science and Engineering 2023年第4期16卷 381-389页

作者： Shuang-qing Zhang Jia-chun Liu Biao Huang Jian Zhang The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China School of Civil and Environmental Engineering Ningbo UniversityNingbo 315211China

Considering that we still do not fully understand the behavior of air pockets trapped in rainstorm systems and water flow changes inside pipes,the study of actual geysers presents many *** this study,three-dimensional numerical models were developed to investigate the mechanisms of geyser events triggered by rapid filling flows at different *** results showed that,in the first stage of the water–air mixture of the prototype model,a large amount of air was released quickly,and the subsequent overflow lasted for a more extended *** transport capacity of the downstream pipe,as a critical factor,significantly influenced the water–air interaction of the *** the outlet area and increasing the outlet pressure simultaneously resulted in a stronger *** equivalent density of the water–air mixture increased as the scale decreased during the geyser event.

关键词： Equivalent density Prototype model Storm geyser transport capacity Water-air mixture

Comprehensive Transcriptome Analysis of Auxin Responses in Arabidopsis

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Molecular Plant 2008年第2期1卷 321-337页

作者： Ivan A. Paponov Martina Paponovt William Teale Margit Menges Sohini Chakrabortee James A.H. Murray Klaus Palme Faculty of Biology University of Freiburg Schanzlestrasse 1 79104 Freiburg Germany Institute of Biotechnology University of Cambridge Cambridge CB2 1QT United Kingdom

In plants, the hormone auxin shapes gene expression to regulate growth and development. Despite the detailed characterization of auxin-inducible genes, a comprehensive overview of the temporal and spatial dynamics of auxinregulated gene expression is lacking. Here, we analyze transcriptome data from many publicly available Arabidopsis profiling experiments and assess tissue-specific gene expression both in response to auxin concentration and exposure time and in relation to other plant growth regulators. Our analysis shows that the primary response to auxin over a wide range of auxin application conditions and in specific tissues comprises almost exclusively the up-regulation of genes and iden- tifies the most robust auxin marker genes. Tissue-specific auxin responses correlate with differential expression of Aux/ IAA genes and the subsequent regulation of context- and sequence-specific patterns of gene expression. Changes in transcript levels were consistent with a distinct sequence of conjugation, increased transport capacity and down-regulation of biosynthesis in the temperance of high cellular auxin concentrations. Our data show that auxin regulates genes associated with the biosynthesis, catabolism and signaling pathways of other phytohormones. We present a transcriptional overview of the auxin response. Specific interactions between auxin and other phytohormones are highlighted, particularly the regulation of their metabolism. Our analysis provides a roadmap for auxin-dependent processes that underpins the concept of an ＇auxin code＇-a tissue-specific fingerprint of gene expression that initiates specific developmental processes.

关键词： Alcohol Abstinence Genes transport capacity transcriptomics Tissue-Specific Gene Expression Auxins Arabidopsis Plant Growth Regulators

SOIL EROSION PROCESS RESEARCH AND ITS POTENTIAL IMPACT ON EROSION PREDICTION MODEL DEVELOPMENT

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International Journal of Sediment Research 2005年第4期20卷 350-357页

作者： Chi-hua HUANG1 and Fenli ZHENG2Soil Erosion Research Laboratory, Purdue Univ., West Lafayette, IN 47907-2077, USA. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, CAS and MOWR, Northwestern A & Univ. Soil Erosion Research Laboratory Purdue Univ. West Lafayette IN 47907-2077 USA State Key Laboratory of Soil Erosion and Dryland Fanning on the Loess Plateau Institute of Soil and Water Conservation CAS and MOWR Northwestern A & Univ. Yangling Shaanxi 712100 China

This paper highlights past efforts in developing erosion process concepts that lead to the development of the current process-based erosion prediction model, i.e., WEPP. Recent progress includes the development of a multiple-box system that can simulate hillslope hydrologic conditions. Laboratory procedures enable the quantification of near-surface hydrologic effects, i.e., artesian seepage vs. drainage, on the soil erosion process and sediment regime, flow hydraulics, and sediment transport and deposition processes. These recent findings improve soil erosion science and provide new erosion control strategies that may have additional environmental benefits relative to the traditional erosion control practices. The paper also discusses the potential impacts of the erosion process on erosion model development and future research directions of soil erosion process research and model development .

关键词： Soil erosion process Erosion prediction model Surface condition Spatial and temporal variability transport capacity

An introduction to network information theory and its implications on wireless communications

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An introduction to network information theory and its implic...