Formulas for structural dynamics: Igor A. Karnovsky and Olga I. Lebed; McGraw-Hill, Inc., New York, N.Y., 2001, pp. 535. Price $38, ISBN 0-07-136712-8.     

Patricio A. A. Laura  Diana V. Bambill 《Ocean Engineering》2002,29(11):1459

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Intertidal Rocky Shore Communities of the Continental Portuguese Coast: Analysis of Distribution Patterns     

Diana Boaventura  Pedro R  Luís Cancela da Fonseca  Stephen J. Hawkins 《Marine Ecology》2002,23(1):69-90

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Predicting satellite visibility     

Diana W. Scott 《Planetary and Space Science》1967,15(12):1895-1911

An Earth satellite can only be observed by optical methods when it is illuminated by sunlight and the observing station is in darkness, with the result that the satellite is in general only visible on two fairly small arcs of its orbit.

In this paper, a graphical method has been developed for predicting the latitudes from which a satellite in a circular orbit is visible, with the particular aim of discovering periods when a satellite may be observed in mid-latitudes in both the northern and southern hemispheres. For near-polar orbits the occurrence of such periods depends critically on the position of the ascending node of the orbit; but for lower inclinations, the periods of visibility become shorter and more frequent, and the orientation of the orbit is less significant.  相似文献   

A revaluation of the rotational speed of the upper atmosphere     

D. G. King-Hele  Diana W. Scott 《Planetary and Space Science》1966,14(12):1339-1365

In this paper the rotational speed of the upper atmosphere, mainly at heights of 200–300 km, is evaluated from the changes in the orbital inclinations of thirteen satellites. The values obtained represent the mean rotational speed over the latitudes covered by the satellites, at dates between late 1962 and early 1966, i.e. when solar activity was low.

If the angular velocity of the atmosphere is taken as Λ times that of the Earth, the values of Λ found are mostly between 1.0 and 1.6 with estimated S.D. between 0.1 and 0.25. If we exclude two values at heights above 300 km and one anomalous value, the mean of the remaining ten values of Λ obtained is 1.27, with r.m.s. scatter 0.18: this would correspond to an average west-to-east wind of about 100 m/sec in mid-latitudes.  相似文献   

U.S. National climate assessment gaps and research needs: overview,the economy and the international context     

Diana Liverman 《Climatic change》2016,135(1):173-186

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Approaching four decades of forest watershed research at Upper Penticton Creek,British Columbia: A synthesis     

Rita D. Winkler  Diana M. Allen  Tim R. Giles  Brian A. Heise  R. Dan Moore  Todd E. Redding  Dave L. Spittlehouse  Xiaohua Wei 《水文研究》2021,35(5):e14123

Over the past 35 years, the Upper Penticton Creek (UPC) Watershed Experiment has supported forest hydrology research in south-central British Columbia (BC), Canada. This paper provides a synthesis of research results, highlights the challenges facing UPC and identifies new research directions. Clearcutting approximately 50% of two small, snow-dominated (Dfb Koppen classification) watersheds advanced the timing of snowmelt-generated high flows and decreased late-summer low flows, relative to predictions based on pre-treatment regressions. Changes in high flows did not have a significant effect on stream channels due to low stream power, coarse substrate, and limited riparian disturbance. Changes in summer low flows reduced modelled useable fish habitat by 20%–50%. Evaporation averaged 52% of the annual precipitation in the mature forest, was reduced to 30% in a clearcut, and recovered to 40% and 47% in a 10 and 25 year-old stand, respectively. Groundwater recharge to the bedrock was estimated at 19% of annual precipitation, indicating that, even with the large uncertainty associated with this estimate, deep groundwater should not be ignored in the water balance. Suspended sediment, turbidity, and colour increased post-logging; however, chemical surface water quality did not change. Aquatic community structure changed post-logging; and although this affected the processing of organic matter, the effects on habitat quality were considered minimal. The information gained at UPC has supported provincial policies, management guidelines, forest stewardship plans and watershed risk assessments. The undisturbed control watershed, re-growing treatment watersheds and ongoing long-term hydrometric monitoring continue to provide opportunities for future research addressing issues such as the effects of young forests on streamflow and hydrologic recovery, and the influence of climate change on the hydrologic regime.  相似文献   

Artisanal ceramic factories using wood combustion:A nanoparticles and human health study     

Kátia Martinello  James C.Hower  Diana Pinto  Carlos E.Schnorr  Guilherme L.Dotto  Marcos Leandro Silva Oliveira  Claudete G.Ramos 《地学前缘(英文版)》2022,(1):488-497

The ceramics industry,resulting from developments of modern compounds,is a segment of great influence in worldwide sustainability.Artisanal ceramic factories based on wood combustion have significant risks for the creation and discharge of atmosphere nanoparticles(NPs)and ultra-fine particles(UFPs).At present,there is insufficient recognition on the influence of engineered-NPs on the atmosphere and health.Real improvements are indispensable to diminish contact with NPs.The present study demonstrates the main NPs and UFPS present in an area of intense artisanal wood-combustion ceramic manufacturing.Particulate matter was sampled for morphological,chemical,and geochemical studies by sophisticated electron microbeam microscopy,X-Ray Diffraction,and Raman spectroscopy.From NPs configuration(<10 nm)we identify nucleation.Several amorphous NPs(>10 nm)were produced around the studied artisanal ceramic factories.This study presents an indication of the recent information on population and work-related contact to NPs in the artisanal ceramic factories and their influence on health.  相似文献   

Trophic Impacts of Marine Mammals and Seabirds in the Río de la Plata Estuary and the Nearshore Oceanic Ecosystem     

Leandro Bergamino  Diana Szteren  Diego Lercari 《Estuaries and Coasts》2012,35(6):1571-1582

As top predators, marine mammals and seabirds play an important role in structuring marine ecosystems, and their trophic role have become a major issue. In this study, we quantify the trophic impact of marine mammals and seabirds in the Río de la Plata estuary based on a previous trophic mass balance model of this estuary. The model comprised 37 functional groups: 3 species of marine mammals (2 cetaceans: Tursiops truncatus, Pontoporia blainvillei and 1 pinniped: Otaria flavescens), 1 coastal bird group comprising 11 species, 17 fish, 12 invertebrates, 2 zooplanktons, 1 phytoplankton, detritus, and 5 fishing fleets. Model results showed that seabirds, O. flavescens and P. blainvillei, are apex predators, with high levels of niche overlap among them, suggesting competition for similar resources such as fish species. Marine mammals and seabirds produce negative effects on commercially important species, while, at the same time, indirect positive effects (increase of the biomass) were also detected in some groups related to trophic cascade effects.  相似文献   

Mixing processes in hydrothermal spring systems and implications for interpreting geochemical data: a case study in the Cappadocia region of Turkey     

Mustafa Afsin  Diana M. Allen  Dirk Kirste  U. Gokcen Durukan  Ali Gurel  Ozcan Oruc 《Hydrogeology Journal》2014,22(1):7-23

Mixing is a dominant hydrogeological process in the hydrothermal spring system in the Cappadocia region of Turkey. All springs emerge along faults, which have the potential to transmit waters rapidly from great depths. However, mixing with shallow meteoric waters within the flow system results in uncertainty in the interpretation of geochemical results. The chemical compositions of cold and warm springs and geothermal waters are varied, but overall there is a trend from Ca–HCO₃ dominated to Na–Cl dominated. There is little difference in the seasonal ionic compositions of the hot springs, suggesting the waters are sourced from a well-mixed reservoir. Based on δ¹⁸O and δ²H concentrations, all waters are of meteoric origin with evidence of temperature equilibration with carbonate rocks and evaporation. Seasonal isotopic variability indicates that only a small proportion of late spring and summer precipitation forms recharge and that fresh meteoric waters move rapidly into the flow system and mix with thermal waters at depth. ³H and percent modern carbon (pmC) values reflect progressively longer groundwater pathways from cold to geothermal waters; however, mixing processes and the very high dissolved inorganic carbon (DIC) of the water samples preclude the use of either isotope to gain any insight on actual groundwater ages.  相似文献   

Experimental analysis of different software packages for orientation and digital surface modelling from UAV images   总被引：1，自引：0，他引：1  

Giovanna Sona  Livio Pinto  Diana Pagliari  Daniele Passoni  Rossana Gini 《Earth Science Informatics》2014,7(2):97-107

The use of UAVs finds application in a variety of fields, among which are the small scale surveys for environmental protection application. In this frame some experimental tests were carried out at Politecnico di Milano to assess metric accuracies of images acquired by UAVs and derived photogrammetric products. A block of 5 strips and 49 photos was taken by fixed wing system SenseFly, carrying a camera Canon Ixus 220HS on a rural area included in an Italian Park. Images are processed through bundle adjustment, automatic DEM extraction and orthoimages production steps with several software packages, with the aim to evaluate their characteristics, capabilities and weaknesses. The software packages tested were Erdas-LPS, EyeDEA (University of Parma), Agisoft Photoscan, Pix4UAV, PhotoModeler Scanner. For the georeferencing of the block 16 pre-signalized ground control points were surveyed in the area through GPS (NRTK survey). Comparison of results is given in terms of differences among orientation parameters and their accuracies. Moreover, comparisons among different digital surface models are evaluated. Furthermore, exterior orientation parameters, image points and ground points coordinates, obtained by the various software packages, were used as initial values in a comparative adjustment made by scientific in-house software. Paper confirms that computer vision software are faster in computation and, even if their main goal is not to pursue high accuracy in points coordinates determination, they seems to produce results comparable to those obtainable with standard photogrammetric approach. Agisoft Photoscan seems in this case to yield the best results in terms of quality of photogrammetric products.  相似文献