Discovery of absorption features of the accretion disc corona and systematic acceleration of the X-ray burst rate in XB 1323-619     

M. J. Church  D. Reed  T. Dotani  M. Ba&#;uci&#;ska-Church  A. P. Smale 《Monthly notices of the Royal Astronomical Society》2005,359(4):1336-1344

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A computer-aided framework for subsurface identification of white shark pigment patterns     

M Dureuil  AV Towner  LG Ciolfi  LA Beck 《African Journal of Marine Science》2015,37(3):363-371

Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark's head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images.  相似文献   

西藏近35年地表湿润指数变化特征及其影响因素   总被引：8，自引：0，他引：8  

杜军  李春  拉巴  罗布次仁  廖健 《气象学报》2009,67(1):158-164

利用1971-2005年西藏25个气象站月平均最高气温、最低气温、风速、相对湿度、日照时数、降水量等资料,应用Penman-Monteith模犁计算了最大潜在蒸散、地表湿润指数,分析了其空间分布、年际变化特征及季节差异,并讨论了影响地表湿润指数变化的气象因子.研究表明:近35年,西藏年降水量表现为显著的增加趋势,增幅为15.0 mm/(10 a);年最大潜在蒸散呈不同程度的减小趋势,为-4.6--71.6 mm/(10 a).阿里地区西南部、聂拉木年地表湿润指数为不显著的减小趋势,其他各地均呈增大趋势,增幅为0.02-0.09.就西藏平均而言,年地表湿润指数以0.04/10 a的速率显著增大,尤其足近25年增幅更为明显.各季节地表湿润指数也表现为增大趋势,以夏季增幅最明显.20世纪70年代剑80年代主要表现为以低温低湿为主的年际变化特征,进入90年代后,气温持续升高,地表湿润指数明显增加,呈现山暖湿型的气候特征.降水量和相对湿度的明显增加,以及平均气温日较差的显著减小是地表湿润指数显著增加的主要原因,平均风速和日照时数的明显减少,在湿润指数增加趋势中也起着重要作用.  相似文献   

Time-resolved spectroscopy of the sdBV V338 Serpentis     

R. H. Østensen  J. H. Telting  R. Oreiro  U. Heber  E. De Beck  M. Reed 《Astrophysics and Space Science》2010,329(1-2):167-174

We obtained 1955 high-resolution spectra of the high-amplitude pulsating subdwarf B star V338 Ser with the FIES spectrograph at the 2.5 m Nordic Optical Telescope covering 4 full nights in May–June 2009. Here we present the first results from phase-folding the data on the main pulsation mode, as revealed by simultaneous B-band photometry obtained with the Mercator 1.25 m and Baker 0.4 m telescopes. We compare the results with a sample line-profile model produced with LTE atmospheres and bruce+kylie.  相似文献   

Analysis and modeling of a tropical-like cyclonein the Mediterranean Sea     

R. J. Reed  Y.-H. Kuo  M. D. Albright  K. Gao  Y.-R. Guo  W. Huang 《Meteorology and Atmospheric Physics》2001,76(3-4):183-202

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The response of coastal marshes to sea-level rise: Survival or submergence?     

Denise J. Reed 《地球表面变化过程与地形》1995,20(1):39-48

In order to maintain an elevation in the intertidal zone at which marsh vegetation can survive, vertical accretion of the marsh surface must take place at a rate at least equal to the rate of relative sea-level rise. Net vertical accretion of coastal marshes is a result of interactions between tidal imports, vegetation and depositional processes. All of these factors are affected, directly or indirectly, by alterations in marsh hydrology which might occur as a result of sea-level rise. The overall response of coastal marshes to relative sea-level rise depends upon the relative importance of the inorganic and organic components of the marsh soil and the impact of increased hydroperiod on net accumulation. The varied combination of factors contributing to sediment supply, and their complexity at the scale of individual marshes, means that predicting the response of suspended sediment concentration in marsh floodwater to any changes which may occur as a result of sea-level rise, at anything other than the local scale is unlikely to be accurate. The impact of sea-level rise on net below-ground production is also complex. The sensitivity of certain species to waterlogging and soil chemical changes could result in a change in species composition or the migration of vegetation zones. Consequently, predicting the net impact of sea-level rise on organic matter accumulation is fraught with difficulties and requires improved understanding of interactions between vegetation, soil and hydrologic processes.  相似文献   

朝鲜半岛的历史地震资料   总被引：1，自引：0，他引：1  

吴戈 《东北地震研究》1994,(1)

朝鲜半岛历史悠久．整理朝鲜半岛地震史料表明，从公元１３年至１９４５年，在半岛上曾经发生过２０７０次历史地震，可堪称是个多地震的地区．这些历史地震资料，对于分析研究中朝邻近地区及其海域的地震活动可能具有很大的参考意义．  相似文献   

Formation of regolith-collapse sinkholes in southern Illinois: Interpretation and identification of associated buried cavities     

S. V. Panno  C. P. Wiebel  P. C. Heigold  P. C. Reed 《Environmental Geology》1994,23(3):214-220

Three regolith-collapse sinkholes formed near the Dongola Unit School and the Pentecostal Church in the southern Illinois village of Dongola (Union County) during the spring of 1993. The sinkholes appeared over a three-month period that coincided with development of a new municipal well. The new well was drilled through clay-rich, valley-fill sediment into karstified limestone bedrock. The piezometric surface of the limestone aquifer is above land surface, indicating the presence of an upward hydraulic gradient in the valley and that the valley fill is acting as a confining unit. Pumping during development of the well lowered the piezometric surface of the limestone aquifer to an elevation below the base of the valley fill. It is hypothesized that drainage of water from the sediments, the resulting loss of hydrostatic pressure and buoyant force in overlying sediments, increased intergranular pressure, and the initiation of groundwater flow toward the well resulted in rapid sediment transport, subsurface erosion, and collapse of the valley-fill sediment. The sinkholes follow an approximately east-west alignment, which is consistent with one of the two dominant alignments of passages of nearby joint-controlled caves. A constant electrode-separation resistivity survey of the school playground was conducted to locate areas that might contain incipient sinkholes. The survey revealed a positive resistivity anomaly trending N75E in the southern part of the study area. The anomaly is linear, between 5 and 10 m wide, and its trend either intersects or is immediately adjacent to the three sinkholes. The anomaly is interpreted to be a series of pumping-induced cavities in the valley-fill sediments that formed over a preexisting crevice in the karstified bedrock limestone.  相似文献   

Lithium tracer-diffusion in an alkali-basaltic melt — An ion-microprobe determination     

R.K. Lowry  S.J.B. Reed  J. Nolan  P. Henderson  J.V.P. Long 《Earth and Planetary Science Letters》1981,53(1):36-40

An ion-microprobe-based technique has been used to measure lithium tracer-diffusion coefficients (D_Li) in an alkali-basaltic melt at 1300, 1350 and 1400°C. The results can be expressed in the form:D_Li=7.5 ×10^?2exp(?27,600/RT)cm²S^?1The results show significantly faster diffusion rates than those previously recorded for other monovalent, divalent and trivalent cations in a tholeiitic melt. Consequently, diffusive transport of ions acting over a given time in a basaltic melt can produce a wider range of transport distance values than hitherto supposed. Hence, it is concluded that great care should be exercised when applying diffusion data to petrological problems.  相似文献   

Lithium diffusion in silicate melts     

G.J. Cunningham  P. Henderson  R.K. Lowry  J. Nolan  S.J.B. Reed  J.V.P. Long 《Earth and Planetary Science Letters》1983,65(1):203-205

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