Testing morphodynamic controls on the location and frequency of river avulsions on fans versus deltas: Huanghe (Yellow River), China

A mechanistic understanding of river avulsion location and frequency is needed to predict the growth of alluvial fans and deltas. The Huanghe, China, provides a rare opportunity to test emerging theories because its high sediment load produces regular avulsions at two distinct nodes. Where the river debouches from the Loess plateau, avulsions occur at an abrupt decrease in bed slope and reoccur at a time interval (607 yrs) consistent with a channel-filling timescale set by the superelevation height of the levees. Downstream, natural deltaic avulsions reoccur at a timescale that is fast (7 yrs) compared to channel-filling timescale due to large stage-height variability during floods. Unlike the upstream node, deltaic avulsions cluster at a location influenced by backwater hydrodynamics and show evidence for episodic downstream migration in concert with progradation of the shoreline, providing new expectations for the interplay between avulsion location, frequency, shoreline rugosity and delta morphology

Abrupt drainage basin reorganization following a Pleistocene river capture

River capture is a dramatic natural process of internal competition through which mountainous landscapes evolve and respond to perturbations in tectonics and climate. River capture may occur when one river network grows at the expense of another, resulting in a victor that steals the neighboring headwaters. While river capture occurs regularly in numerical models, field observations are rare. Here we document a late Pleistocene river capture in the Yimeng Mountains, China that abruptly shifted 25 km^2 of drainage area from one catchment to another. River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating knickpoints and waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape

Abrupt drainage basin reorganization following a Pleistocene river capture

River capture is a dramatic natural process of internal competition through which mountainous landscapes evolve and respond to perturbations in tectonics and climate. River capture may occur when one river network grows at the expense of another, resulting in a victor that steals the neighboring headwaters. While river capture occurs regularly in numerical models, field observations are rare. Here we document a late Pleistocene river capture in the Yimeng Mountains, China that abruptly shifted 25 km^2 of drainage area from one catchment to another. River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating knickpoints and waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape

The dramatic changes and anthropogenic causes of erosion and deposition in the lower Yellow (Huanghe) River since 1952

The Yellow River has been considerably altered over the past half century from human activities. These perturbations provide a rare opportunity to document how this natural system has responded to anthropogenic impacts on channel hydrodynamics. Using a six-decade record data set, I analyze and summarize changing patterns in erosion and sedimentation of a downstream channel with three units (km^3/y, Gt/y, and cm/y), and the response to human impacts upstream. The changing pattern of channel-bed erosion and deposition in the lower reach during 1952–2007 is divided into five phases in terms of erosion and deposition rates and human activities: (1) a rapid and quasi-natural deposition phase (1952–1959, 0.25 km^3/y or 10 cm/y) with few main human effects, (2) a rapid erosion phase (1960–1964, − 0.36 km^3/y or − 14 cm/y) in response to heavy sedimentation in the Sanmenxia reservoir, (3) a rapid deposition phase (1965–1973, 0.32 km^3/y or 13 cm/y) in response to sediment release from the Sanmenxia reservoir, (4) a moderate erosion and deposition phase with a net deposition (1974–1999, 0.10 km^3/y or 4 cm/y) in response to the Sanmenxia reservoir practice of storing clear water and discharging turbid water since 1974 and the intensified soil and water conservation since the 1970s, and (5) a slow erosion phase (2000–2007, − 0.15 km^3/y or − 6 cm/y) in response to the water and sediment regulation and the initial operation of Xiaolangdi reservoir. The total reduction in sediment delivery by this river is 41.0 Gt (giga tons) during 1959–2007. The sediment delivery reduction are dams and reservoirs (51%), soil and water conservation (25%), increased water consumption (19%), and channel sedimentation (13%)

Luminescence Reduced Graphene Oxide Based Photothermal Purification of Seawater for Drinkable Purpose

Getting drinking water from seawater is a hope and long-term goal that has long been explored. Here, we report graphene-loaded nonwoven fabric membranes for seawater purification based on photothermal heating. The photothermal membrane of non-woven fabric loaded with graphene oxide has high light absorption and strong heating effect, and its evaporation rate about 5 times higher than that of non-woven fabric. Under the condition of light intensity of 1 kW m−2, the evaporation rate can reach 1.33 kg m−2 h−1. The results of cell activity test showed that the concentration of bacteria after photothermal membrane treatment decreased significantly. The photothermal membrane can be used for many times without greatly reducing the evaporation efficiency, which means that it is suitable for regional water purification and seawater desalination

Genome Sequence of Mycoplasma capricolum subsp. capripneumoniae Strain M1601

Mycoplasma capricolum subsp. capripneumoniae is the causative agent of contagious caprine pleuropneumonia, a devastating disease of goats listed by the World Organization for Animal Health. Here we report the first complete genome sequence of this organism (strain M1601, a clinically isolated strain from China)

A non-dispersion strategy for large-scale production of ultra-high concentration graphene slurries in water

10.1038/s41467-017-02580-3NATURE COMMUNICATIONS9

Genome-wide analysis of the first sequenced mycoplasma <em>capricolum</em> subsp<em> capripneumoniae</em> Strain M1601

International audienceMycoplasma capricolum subsp. capripneumoniae (Mccp) is a common pathogen of goats that causes contagious caprine pleuropneumonia. We closed the gap and corrected rRNA operons in the draft genome of Mccp M1601: a strain isolated from an infected goat in a farm in Gansu, China. The genome size of M1601 is 1,016,707 bp with a GC content of 23.67%. We identified 915 genes (occupying 90.27% of the genome), of which 713 are protein-coding genes (excluding 163 pseudogenes). No genomic islands and complete insertion sequences were found in the genome. Putative determinants associated with the organism's virulence were analyzed, and 26 genes (including one adhesion protein gene, two capsule synthesis gene clusters, two lipoproteins, hemolysin A, ClpB, and proteins involved in pyruvate metabolism and cation transport) were potential virulence factors. In addition, two transporter systems (ATP-binding cassette [ABC] transporters and phosphotransferase) and two secretion systems (Sec and signal recognition particle [SRP] pathways) were observed in the Mccp genome. Genome synteny analysis reveals a good collinear relationship between M1601 and Mccp type strain F38. Phylogenetic analysis based on 11 single-copy core genes of 31 Mycoplasma strains revealed good collinearity between M1601 and Mycoplasma capricolum subsp. capricolum (Mcc) and close relationship among Mycoplasma mycoides cluster strains. Our genome-wide analysis of Mccp M1601 provides helpful information on the pathogenic mechanisms and genetics of Mccp