Miracle-dz/UniFAR-FTUs huggingface dataset:
Estimation of tree transpiration and response of tree conductance to meteorological variables in desert-oasis system of Northwest China

Transpirations of three dominated tree species, namely Mongol Scotch Pine (Pinus sylvestris var. mongolica Litvin), White elm (Ulmus pumila) and Gansu Poplar (Populus gansuensis Wang et Yang) in oasis shelter forest (Linze site) and of two dominated tree species, namely Euphrates Poplar (Populus euphratica Oliv.) and Russia olive (Elaeagnus angustifolia Linn.) in lowland desert (Erjinaqi site) have been estimated using measured sapflow in summer, autumn and winter, 2002 and in spring, 2003. An ENVIS System was used for each site to measure microclimate variables, soil moisture and sapflow every half an hour, and the study time scale is one day. In the 104 days of observation during the growing season at the Linze site, the average daily sapflow of Gansu Poplar is 9.93 L· d-1, and the average transpiration per unit leaf area is 1.99 mm · d-1. For White elm tree, the daily average sapflow is 4.08 L· d-1, while the daily average transpiration per unit leaf area is 0.49 mm · d-1. The values for Mongol Scotch Pine are 3.91 L· d-1 and 0.25 mm · d-1, respectively. In the total 73 days of observation during the growing season at the Erjinaqi site, the daily average sapflows of Russia olive and Euphrates Poplar are 12.1 and 20.97 L· d-1, respectively, and the average transpirations per unit leaf area are 0.22 and 0.31 mm · d-1, respectively. In the observation period of the growing season, tree conductances of Mongol Scotch Pine, White elm, Gansu Poplar or Russia olive show an exponential relationship with the daily average air temperature or vapour pressure deficit, but the relationship is not so obvious between tree conductance and global radiation. The transpiration process of each tree species is affected by all the observed four environmental variables. The response of tree conductance to different climatic factors changes with tree species. The effect of the same factor to the same tree species is also variable in different growing stages. The sapflow of every tree species is relatively large in later spring to early summer, and low in summer, and then reaches its largest value in later September. In the mid-November, the sapflow is relatively large, especially the deciduous tree species. This may be characteristic of the tree species in Arid Regions of Northwest China.
Changes in the position of the Subtropical Front south of New Zealand since the last glacial period

This study fills an important gap in our understanding of past changes in the Southern Subtropical Front (S-STF) in the southwest Pacific Ocean. Paleo-sea surface temperatures (SST) were estimated from planktic foraminiferal census counts from cores straddling the modern S-STF in the Solander Trough, south of New Zealand. The estimated SST were compared for 6 time slices; glacial period (25-21 ka), Last Glacial Maximum (LGM; 21-18 ka), early deglaciation (18-16 ka), late deglacial/early Holocene period (14-8 ka), mid-Holocene period (8-4 ka), and late Holocene period (4-0 ka). The position of the S-STF was determined by two methods: (1) the location of the 10 degrees C isotherm and (2) the location of the highest SST gradients. These new results suggest that the S-STF was not continuous between east and west of New Zealand during the glacial period. Steep SST gradients indicate that a strong S-STF rapidly shifted south during the LGM and early deglaciation. During the late deglacial and Holocene periods the position of the S-STF differs between the two methods with reduced SST gradients, suggesting amore diffuse S-STF in the Solander Trough at this time. The glacial SST data suggest that the S-STF shifted north to the west of New Zealand, while to the east there was a stronger SST gradient across the front. This was possibly the result of an increased wind stress curl, which could have been caused by stronger, or more northerly Southern Hemisphere westerly winds (SHWW), or a merging of the SHWW split jet in this region.
Inter-annual variability of the global terrestrial water cycle

Abstract. Variability of the terrestrial water cycle, i.e. precipitation (P), evapotranspiration (E), runoff (Q) and water storage change (ΔS) is the key to understanding hydro-climate extremes. However, a comprehensive global assessment for the partitioning of variability in P between E, Q and ΔS is still not available. In this study, we use the recently released global monthly hydrologic reanalysis product known as the Climate Data Record (CDR) to conduct an initial investigation of the inter-annual variability of the global terrestrial water cycle. We first examine global patterns in partitioning the long-term mean P‾ between the various sinks E‾, Q‾ and ΔS‾ and confirm the well-known patterns with P‾ partitioned between E‾ and Q‾ according to the aridity index. In a new analysis based on the concept of variability source and sinks we then examine how variability in the precipitation σP2 (the source) is partitioned between the three variability sinks σE2, σQ2 and σΔS2 along with the three relevant covariance terms, and how that partitioning varies with the aridity index. We find that the partitioning of inter-annual variability does not simply follow the mean state partitioning. Instead we find that σP2 is mostly partitioned between σQ2, σΔS2 and the associated covariances with limited partitioning to σE2. We also find that the magnitude of the covariance components can be large and often negative, indicating that variability in the sinks (e.g. σQ2, σΔS2) can, and regularly does, exceed variability in the source (σP2). Further investigations under extreme conditions revealed that in extremely dry environments the variance partitioning is closely related to the water storage capacity. With limited storage capacity the partitioning of σP2 is mostly to σE2, but as the storage capacity increases the partitioning of σP2 is increasingly shared between σE2, σΔS2 and the covariance between those variables. In other environments (i.e. extremely wet and semi-arid–semi-humid) the variance partitioning proved to be extremely complex and a synthesis has not been developed. We anticipate that a major scientific effort will be needed to develop a synthesis of hydrologic variability.
Un Hegetotheriidae (Mammalia, Notoungulata) basal del Mioceno temprano de Patagonia

Hegetotheriidae represents one of the most derived clades within the Order Notoungulata. Already diversified in the late Oligocene, its members, many of them with gliriform appearance, are conspicuous components of the terrestrial South American mammalian faunas up to the Pleistocene. However, the knowledge of their diversity during the Colhuehuapian South American Land Mammal Age (early Miocene) is still imperfect. Here it is described a new hegetotheriid, Hegetotheriopsis sulcatus n. gen. et sp. , represented by a skull fragment with partial dentition from Colhuehuapian beds of the Sarmiento Formation at Bryn Gwyn, central Patagonia. Many mandibular fragments with teeth from this locality and other putative coeval localities at Northern Patagonia are referred tentatively to this new taxon.
Edge wave trapping and amplification on barred beaches

Theoretical predictions show that edge waves may be trapped on bars, providing a possible mechanism for bar growth. Simple solutions to the linear shallow water equations reveal that bar trapping is controlled by the depth of the water over the bar hbar and the geometry of the inshore trough relative to the bar. For specific geometries, amplification over the bar approaches an order of magnitude or more as the phase speed approaches , where amplification is defined as the surface displacement over the bar relative to the surface displacement at the shoreline. The amplification increases with the cross-shore length scales of the profiles. The amplification is somewhat frequency dependent, generating stronger currents at the location of the bar in specific frequency ranges. Previous work showed that particular edge wave modes have the correct length scales to generate beach features such as bars and beach cusps, but field observations, notably shoreline run-up data, frequently show no evidence of edge wave energy being concentrated at the appropriate frequencies. However, for bar-trapped modes, edge wave energy is concentrated at the location of the bar; therefore this edge wave energy will not necessarily be evident in shoreline measurements. Strong correlation exists between the energy distribution of the longshore component of the orbital velocity observed in data collected at Superduck, October 11, 1986, and the distribution expected for a white edge wave spectrum at the shoreline. This suggests that bar-trapped edge waves exist, in particular, at incident wave frequencies.
A possible effect of ionospheric perturbations associated with the Sumatra earthquake, as revealed from subionospheric very‐low‐frequency (VLF) propagation (NWC‐Japan)

The observation of subionospheric very‐low‐frequency (VLF) propagation between the transmitter NWC (Australia) (frequency 19.8 kHz) and our three receiving sites in Japan (Chofu, Chiba, and Kochi) are used to find a possible precursor of ionospheric perturbations to the Sumatra earthquake in late December 2004. Night‐time fluctuations in VLF propagation data at all three sites have exhibited significant enhancements from 4 days before the earthquake, which is likely to be a precursor to the earthquake.
Influence of Structural Heterogeneity on Diffusion of CH4 and CO2 in Silicon Carbide-Derived Nanoporous Carbon

We investigate the influence of structural heterogeneity on the transport properties of simple gases in a Hybrid Reverse Monte Carlo (HRMC) constructed model of silicon carbide-derived carbon (SiC-DC). The energy landscape of the system is determined based on free energy analysis of the atomistic model. The overall energy barriers of the system for different gases are computed along with important properties, such as Henry constant and differential enthalpy of adsorption at infinite dilution, and indicate hydrophobicity of the SiC-DC structure and its affinity for CO2 and CH4 adsorption. We also study the effect of molecular geometry, pore structure and energy heterogeneity considering different hopping scenarios for diffusion of CO2 and CH4 through ultramicropores using the Nudged Elastic Band (NEB) method. It is shown that the energy barrier of a hopping molecule is very sensitive to the shape of the pore entry. We provide evidence for the influence of structural heterogeneity on self-diffusivity of methane and carbon dioxide using molecular dynamics simulation, based on a maximum in the variation of self-diffusivity with loading. A comparison of the MD simulation results with self-diffusivities from quasi-elastic neutron scattering (QENS) measurements and, with macroscopic uptake-based low-density transport coefficients, reveals the existence of internal barriers not captured in MD simulation and QENS experiments. Nevertheless, the simulation and macroscopic uptake-based diffusion coefficients agree within a factor of 2–3, indicating that our HRMC model structure captures most of the important energy barriers affecting the transport of CH4 in the nanostructure of SiC-DC.
Global patterns in efficiency of particulate organic carbon export and transfer to the deep ocean

The ocean's biological carbon pump is a key component of the global carbon cycle. Only a small fraction of the carbon fixed by primary production is exported to the deep ocean, yet this flux sets to first order the efficiency with which carbon is sequestered out of further contact with the atmosphere on long time scales. Here we examine global patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface ocean, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep ocean. Previous studies have found a positive correlation between Teff and deep ocean calcite fluxes recovered from sediment traps, implying that ballasting by calcium carbonate may play an important role in regulating Teff. An alternative explanation is that this correlation is not causative, as regions where the dominant biomineral phase is calcite tend to be subtropical systems, which are hypothesized to produce sinking aggregates highly resistant to degradation. We attempt to distinguish between these alternative hypotheses on the control of Teff by examining the relationship between Teff and biomineral phases exported from the upper ocean, rather than those collected in deep traps. Global scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper ocean, but uncorrelated with calcium carbonate export flux. We hypothesize that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper ocean, rather than the availability of calcium carbonate for ballasting.
Modes of Occurrence and Cleaning Potential of Trace Elements in Coals from the Northern Ordos Basin and Shanxi Province, China

Based on the analyses of 43 elements in 16 samples of the raw coal and feed coal collected from the northern Ordos basin and Shanxi Province, the modes of occurrence of these elements were studied using the method of cluster analysis and factor analysis, and the cleaning potential of the hazardous elements relatively enriched in the coals was discussed by analyzing six samples of the cleaned coal from the coal-washing plants and coal cleaning simulation experiments. The results shows that the elements Br and Ba show a strong affinity to the organic matter, Cs, Cd, Pb, Zn and Hg partly to the organic matter, and the other trace elements are mainly associated with the mineral matter. Cs, Mo, P, Pb,Zn and S have positive correlations with the two principal factors, reflecting the complexity of their modes of occurrence.Some elements that were thought to show a faint relationship (Be with S and Sb with carbonates) in other rocks are found to have a strong interrelation in the coals. Clay minerals (mainly kaolinite) dominate in the coals, and Ta, Th, Ti, Sc, REE,Hf, U, Se, W, V, Nb, Mo, Al, P, Cr, Pb and Zn are distributed mostly in kaolinite, while K, Rb, Cs, and Na have much to do with illite. Conventional cleaning can reduce the concentrations of most hazardous elements in various degrees. The hazardous elements S, As, Sb, Se, Mo, Pb, Cd and Hg relatively enriched in some coals from the area studied have a relatively high potential of environmental risks. However, by physical coal cleaning processes, more than 60% of As and Hg were removed, showing a high degree of removal, more than 30% of Sb, as well as S, Pb and Cd partly associated with the inorganic matter were removed. Se and Mo showing a relatively low degree of removal could be further removed by deep crushing of the coal during physical cleaning processes, and the concentrations of S, Pb, Cd and Hg with a partial association with the organic matter could be decreased in such ways as the coal blending. Cluster analysis together with factor analysis is a rap
Magnetisation and demagnetisation of trapped field stacks in a superconducting machine for electric aircraft

This research presents a comprehensive and innovative approach to investigating the magnetisation and cross-field demagnetisation behaviour of high-temperature superconducting (HTS) coated conductors (CCs) in practical superconducting machines. This study introduces several novel contributions, including the operation of the machine in propulsion energy conversion mode, the exploration of harmonics interaction in a real electric machine environment involving CCs, and the extraction of these harmonics as cross-field components. A 2D electromagnetic-thermal coupled numerical model employing the finite element method has been developed and validated against experimental data to simulate a partially superconducting machine. Upon magnetisation, the HTS stacks effectively operate as trapped field magnets, generating rotor fields for motor operation. With a peak magnetic flux density of 462 mT of the trapped field stacks (TFSs) in the air gap, the average values of the fundamental and fifth harmonics of the tangential magnetic flux density experienced by the TFSs were observed to be 25 mT and 1.75 mT, respectively. The research has thoroughly examined the impact of cross-field demagnetisation parameters including amplitude and frequency on the demagnetisation of TFSs. Furthermore, the study has also investigated the magnetisation losses occurring in various layers of HTS tapes, encompassing the HTS layer, magnetic substrate layer, and silver stabiliser at different amplitudes and frequencies. Two tape structures, namely a semi-homogenised model and a multi-layered model, have been analysed in terms of magnetisation loss. Additionally, insights into the shielding effect and skin effect at high frequencies were obtained, offering valuable information on the performance of HTS TFSs exposed to high frequency scenarios especially in high-speed machines for electric aircraft. The research outcomes are anticipated to provide valuable knowledge for the design and optimisation of HTS rotors employing TFSs in superconducting machines, contributing to the advancement of superconducting machine technology.
Historical archaeology of the 19th century caravan trade in north-eastern Tanzania: a zooarchaeological perspective

This zooarchaeological study examined animal economies practiced by local communities against the context of the expansion of the caravan trade in eastern Africa during the nineteenth century. Specific objectives were to establish whether: a) animal economies in areas crossed by caravan trade routes were transformed as a result of expanding trade and the demand for supplies; b) new herd management strategies were adopted by local communities to ensure production of surpluses for exchange; and c) the expansion of this trade caused subsistence stress for local communities. The study area is the Lower Pangani River Basin, north-eastern Tanzania. The three studied riparian island settlements of Ngombezi, Old Korogwe and Kwa Sigi are mentioned in the nineteenth-century European accounts as caravan halts in the Lower Pangani. These were identified through archaeological survey and oral interviews - using the nineteenth-century accounts as a guide to their likely locations. Excavation exposed evidence for human settlements dating to the late seventeenth or early eighteenth centuries AD, and materials recovered include over 30,000 pieces of animal bone, 39,000 potsherds, 4,020 local and imported beads, metal objects, worked bones, remains of flintlock muskets and coins. The analysis of the faunal remains indicates that domestic livestock, a wide range of wild animals, and locally caught fish, were all being consumed at these settlements. The proportion of wild fauna in the assemblage suggests their significant contribution to the diet. At Ngombezi where the longest dated sequence was revealed, such a consumption pattern of mixing domestic and wild resources is not significantly different from that of the pre-nineteenth-century levels, suggesting that the integration of these settlements into the caravan trade network had limited effects on food procurement strategies and consumption patterns. There is a general lack of evidence that young animals were slaughtered, which would be indicative of consumption pressure on domestic stock, as the majority of domestic stock was slaughtered after reaching maturity age - over 3 years for cattle and over 2 years for sheep and goat. These major findings contradict arguments made by historians that the caravan trade had a transformative effect on communities lying along the main trade routes in the region, though additional research at other sites is needed to strengthen this argument.
Graptolite faunas of the Llandovery "phtanites" at Les Fresnaies (Chalonnes-sur-Loire, southeastern Armorican Massif): Palaeontology and biostratigraphy

In the SE of the Armorican Massif (France), the Ordovician-Silurian transition and the lower part of the Silurian are exposed at the locality Les Fresnaies at Chalonnes-sur-Loire. The Silurian graptolitic "phtanites" (black cherts) are richly fossiliferous. Detailed sampling allows a description of the graptolite faunas and a precise stratigraphical analysis of the succession that comprises the whole of the Rhuddanian and Aeronian stages. Both the Llandovery graptolite assemblages and the lithologies of Les Fresnaies are similar to those of other lower Silurian successions throughout peri-Gondwanan Europe, like Portugal, Spain, Sardinia, Bohemia, Germany and Carnic Alps, and in the Middle East (Jordan and Saudi Arabia).
Analysis & Simulation of the Deep Sea Acoustic Channel for Sensor Networks

Nearly 70% of our planet is composed of an aquatic environment, however, due to the lack of appropriate scientific tools and also the relative hostility of the acquatic environment, much of it still remains unexplored. With the advent of global climatic changes, a pronounced energy crisis and changing ecological habitats understanding the oceans of our planet is of vital importance. Monitoring the aquatic environment continually and effectively for oceanographic data collection, offshore exploration, efficient navigation, disaster prevention and monitoring, marine bio sciences data collection, power source exploration and maintenance can now be made possible with the deployment of underwater sensor nodes (USNs). As in terrestrial wireless sensor networks (WSNs), usage of USNs deployed across a large area of the ocean in an underwater wireless sensor networks (UWSNs) can greatly enhance the quality of data collected within the aquatic environment. Recent advancements in unmanned underwater vehicles (UUVs) greatly extends the reach and applicability of UWSNs by enabling the integration of autonomous underwater vehicles (AUVs) acting as mobile sensor nodes (MSNs) for the purposes of underwater resource exploration and also multi-vehicle & diver coordinated collaborative exploration missions for conducting complex investigations, while also enabling autonomous navigational and location determination methodologies. However, since radio frequency (RF) transmissions do not work underwater and optical communication is only suitable for short distances, an UWSN consists of a number of mobile and static nodes that usually communicate using the acoustic channel. Using the acoustic channel for communication causes an UWSN to contend with the issues of high transmission power requirements, rapidly changing channel characteristics, multi-path echoes, possible high ambient noise and interference, high and varying propagation delays and natural ocean currents in addition to the challenges posed by simple WSNs. As such, in order to examine the practices used by UWSNs for successful off-shore deep sea deployments this document first analyzes the underwater channel acoustic propagation model and also looks briefly at the characteristics of the underwater transducers along with the unique effect that they pose upon sonar based communication systems. The document then goes on to exploring the state of the art in UWSNs design paradigms followed by an analysis of areas that warrant research and a discussion of the work carried out during this thesis investigation along with a conclusion highlighting the contributions it makes.