Synergistic effects of vegetation layers of maize and potato intercropping on soil erosion on sloping land in Yunnan Province, China

This is an accepted manuscript of an article published by Springer in Journal of Mountain Science on 04/03/2020, available online: https://doi.org/10.1007/s11629-019-5392-0 The accepted version of the publication may differ from the final published version.Intercropping, as an overyielding system, can decrease soil erosion on sloping land through the presence of dense canopy covers. However, the structure mechanism in canopy is still unclear. We conducted a two-year field experiment on runoff plots, exploring whether the interaction between vegetation layers reduce soil erosion in maize and potato intercropping systems. The maize, potato, and weed layers in the intercropping system were removed by a single layer, two layers and three layers, respectively (total of 8 treatments including all layers removed as the control). Then, throughfall, runoff and sediment were measured at the plot and row scale on a weekly basis. Based on the difference between each treatment and the control, we calculated and found a relative reduction of runoff and sediment by any combination of the two vegetation layers greater than the sum of each single layer. In 2016 and 2017, the highest relative reduction of runoff reached 15.65% and 46.73%, respectively. Sediment loss decreased by 33.96% and 42.77%, respectively. Moreover, runoff and sediment reduced by the combination of all vegetation layers (no layers removed) was also larger than the sum of that by each single layer. In 2016 and 2017, the highest relative reduction of runoff reached 7.32% and 3.48%, respectively. So, there were synergistic effects among multi-level (two or three layers) vegetation layers in terms of decreasing soil erosion on sloping land. Maize redistributes more throughfall at the maize intra-specific row and the maize and potato inter-specific, which is favorable for the synergistic effect of reducing soil erosion. This finding shows an important mechanism of maize and potato intercropping for soil and water conservation, and may promote the application of diverse cropping systems for sustainable agriculture in mountainous areas.Published versio

Regio- and stereoselective organocatalyzed relay glycosylations to synthesize 2-amino-2-deoxy-1,3-dithioglycosides

Herein, we describe a novel methodology for the regio-and stereoselectiveconvergent synthesis of 2-amino-2-deoxy-dithioglycosides via one-potrelay glycosylation of 3-O-acetyl-2-nitroglucal donors.This unique organo-catalysis relay glycosylation features excellentsite- and stereoselectivity, good to excellent yields, mild reactionconditions, and broad substrate scope. 2-Amino-2-deoxy-glucosides/mannosidesbearing 1,3-dithio-linkages were efficiently obtained from 3-O-acetyl-2-nitroglucal donors in both stepwise and one-potglycosylation protocols. The dithiolated O-antigen of E. coli serogroup 64 was successfully synthesizedusing this newly developed method.Bio-organic Synthesi

Existence of a continental-scale river system in eastern Tibet during the late Cretaceous–early Palaeogene

The establishment of continental-scale drainage systems on Earth is largely controlled by topography related to plate boundary deformation and buoyant mantle. Drainage patterns of the great rivers in Asia are thought to be highly dynamic during the Cenozoic collision of India and Eurasia, but the drainage pattern and landscape evolution prior to the development of high topography in eastern Tibet remain largely unknown. Here we report the results of petro-stratigraphy, heavy-mineral analysis, and detrital zircon U-Pb dating from late Cretaceous–early Palaeogene sedimentary basin strata along the present-day eastern margin of the Tibetan Plateau. Similarities in the provenance signatures among basins indicate that a continental-scale fluvial system once drained southward into the Neo-Tethyan Ocean. These results challenge existing models of drainage networks that flowed toward the East Asian marginal seas and require revisions to inference of palaeo-topography during the Late Cretaceous. The presence of a continent-scale river may have provided a stable long-term base level which, in turn, facilitated the development of an extensive low-relief landscape that is preserved atop interfluves above the deeply incised canyons of eastern Tibet

Measurement of Cosmic-ray Muon-induced Spallation Neutrons in the Aberdeen Tunnel Underground Laboratory

AbstractMuon-induced neutrons are one of the major backgrounds to various underground experiments, such as dark matter searches, low-energy neutrino oscillation experiments and neutrino-less double beta-decay experiments. Previous experiments on the underground production rate of muon-induced neutrons were mostly carried out either at shallow sites or at very deep sites. The Aberdeen Tunnel experiment aims to measure the neutron production rate at a moderate depth of 611 meters water equivalent. Our apparatus comprises of six layers of plastic-scintillator hodoscopes for tracking the incident cosmic-ray muons, and 760 L of gadolinium-doped liquid-scintillator for both neutron production and detection targets. In this paper, we describe the design and the performance of the apparatus. The preliminary result on the measurement of neutron production rate is also presented

Properties and application of carbon composite brick for blast furnace hearth

A type of carbon composite brick was produced via the microporous technique using natural flack graphite, α-Al2O3 and high-quality bauxite chamotte (Al2O3≥87 mass%) as raw materials with fine silicon powder as additive. The composition and microstructure of the obtained carbon composite were characterized using chemical analysis, XRD and SEM with EDS. The high temperature properties of thermal conductivity, oxidization and corrosion by molten slag and hot metal of the composite were analyzed. Based on these, the type of carbon composite brick worked in a blast furnace hearth for six years was further sampled at different positions. The protective layer was found and its chemical composition and microscopic morphology were investigated. It is found that the carbon composite brick combines the good properties of both the conventional carbon block and ceramic cup refractory. The protective layer near the hot face consists of two separated sublayers, i.e. the slag layer and the carbon layer. A certain amount of slag phase is contained in the carbon layer, which is caused by the reaction of coke ash with the refractory. No obvious change in the chemical composition of the protective layer along the depth of the sidewall is found. This work provides a useful guidance for the extension of the lifetime of blast furnace hearths

Effects of seed tuber weight on potato as influenced by other factors under different ecological conditions in Sichuan

study was carried out to investigate these effects and their interactions with effects of the other factors in sub-tropical double cropping systems. When evaluated at constant spacing, seed tuber weight significantly affected tuber yield in all conditions under study although seed origin, variety, altitude and season muddled these effects in varying degrees. The effects of seed tuber weight could be attributed to more main stems per plant from heavier seed tubers, resulting in more tubers produced per plant and thus per Unit area. When number of sprouts was set equal per unit area, effect of weight of seed tubers on final tuber yield per unit area was absent in seed tuber weight range from 22 to 124g. However, lighter seed tubers tended to increase leaf area per plant thus compensating the lower plant stand, with larger progeny tubers achieved. If calculated at a per stem basis the numbers of tubers produced and the tuber yields were different for the seed weight treatments; these differences were confounded by seed age effects. The number of tubers produced per unit area largely determined plant yield because the varieties used produced few tubers per plant whereas variation was caused by seed weight or seed density

Exploring aquaporin functions during changes in leaf water potential

Maintenance of optimal leaf tissue humidity is important for plant productivity and food security. Leaf humidity is influenced by soil and atmospheric water availability, by transpiration and by the coordination of water flux across cell membranes throughout the plant. Flux of water and solutes across plant cell membranes is influenced by the function of aquaporin proteins. Plants have numerous aquaporin proteins required for a multitude of physiological roles in various plant tissues and the membrane flux contribution of each aquaporin can be regulated by changes in protein abundance, gating, localisation, posttranslational modifications, protein:protein interactions and aquaporin stoichiometry. Resolving which aquaporins are candidates for influencing leaf humidity and determining how their regulation impacts changes in leaf cell solute flux and leaf cavity humidity is challenging. This challenge involves resolving the dynamics of the cell membrane aquaporin abundance, aquaporin sub-cellular localisation and location-specific post-translational regulation of aquaporins in membranes of leaf cells during plant responses to changes in water availability and determining the influence of cell signalling on aquaporin permeability to a range of relevant solutes, as well as determining aquaporin influence on cell signalling. Here we review recent developments, current challenges and suggest open opportunities for assessing the role of aquaporins in leaf substomatal cavity humidity regulation.Caitlin S. Byrt, Rose Y. Zhang, Isobel Magrath, Kai Xun Chan, Annamaria De Rosa, and Samantha McGaughe