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121.
辽东复州湾中石炭世地层兼论华北地台中石炭统的划分 总被引:3,自引:0,他引:3
华北地台中石炭统本溪组一般仅代表中石炭世晚期沉积。从已知的几十个海陆交互相本溪组剖面来看,其中(虫筳)类生物群为Fusulina-Fusulinella带;牙形石生物群为Idtognathodus magnificus-Ⅰ.claviformis-Neognathodus ruondyi带,在整个华北地台均可依此进行对比。但在辽东半岛南缘的复州湾一带,中石炭世沉积特征却恰好与本溪剖面相反,下部层段以灰岩为主,上部层段以碎屑岩为主。下部含6层灰岩,(虫筳)类以Profusulinella的丰富种群为特征,可建立Profusulinella带,并可进而划分为3个亚带。牙形石则为Idiognathoides sinuatus-Ⅰ.corrugatus-Declinognathodus lateralis带。复州湾含灰岩为主的下部层段和本溪含碎屑岩为主的下部层段对比,依前者之生物组合建立本溪组下部复州湾段(c21),代表华北地台中石炭世早期沉积;复州湾以碎屑岩为主的上部层段和本溪含5层灰岩的上部层段对比,依后者之生物组合限定为本溪组上部牛毛岭段(c22),代表华北地台中石炭世晚期沉积。 相似文献
122.
新疆小热泉子铜矿区构造特征及成矿模式 总被引:3,自引:0,他引:3
新疆小热泉子铜矿区总体为一NW-SE走向的不协调短轴复背斜,后期有SN向次级褶皱叠加。区内NW向断裂发育,均为EW向大断裂之分支断裂,规模小,无推覆性质,主要矿床(Ⅰ号矿床)呈较为典型的立交桥式双层成矿模式。矿床成因类型为中温热液充填-交代型铜(锌)矿床。 相似文献
123.
ThisstudywassupportedbytheStateEducationalCommittee(SEC)ofChina.INTRODUCTIONThedissolvedorganiccarbon(DOC),ordissolvedorganicmatter(DOM),isoneofthemostimPortantorganiccarbonreservoiroftheworld,whichmayaffectthecontentofCO2intheatmospherewithatime-scaleof1OOO~1OOOOyears(Hedges,1992).Theratesofproduction,degradationortransPortationofDOCareseveralmaindynamicalparametersofDOCintheeu-photiclayer.Inthispaper,wefocusonthediurnalvariationsofDOCinordertoestimatetheseparameters.METso… 相似文献
124.
Toshiro Saino Shaoling Shang Yoshihisa Mino Koji Suzuki Hideaki Nomura Sei-ichi Saitoh Hideo Miyake Toshiyuki Masuzawa Koh Harada 《Journal of Oceanography》1998,54(5):583-592
A sediment trap experiment was carried out in conjunction with an over flight of Ocean Color Temperature Scanner (OCTS) on
board Advanced Earth Observing Satellite (ADEOS) at 40°N, 143°E off Sanriku in April to May 1997. Short term variability of
particle fluxes was examined at depths of 450 m and 600 m from April 6 to May 1 with a sampling interval of two days, and
at 450 m with one day interval from 2nd to 10th May. Daily averaged mass flux at 450 m and 600 m was 815 mg m−2d−1 and 862 mg m−2d−1, respectively. A sharp increase in mass flux was observed during the period from April 26 to April 29 with the highest mass
flux of 8 g m−2d−1. About 85% of the total mass flux for the entire duration (26 days) was collected within these 4 days. Trapped material during
the peak flux period was mainly composed of diatoms dominated byThalassiosira spp. and resting spores ofChaetoceros spp. This suggested that the peak flux was the result of (a) diatom bloom(s) in the euphotic column. Current meter records
at 420 m showed that on April 26 and 27, the period when the peak flux was observed, the southwestward current had diminished
in strength and changed its direction northwestward. Low current speeds appeared to have enhanced trap efficiency to help
form the peak flux. A time series of OCTS Intensive-LAC (Local Area Coverage: Region B) images from mid-March to early May
was examined todetect phytoplankton bloom(s). In the March 26th Chl image, high concentration region was restricted to the
southwest off Cape Erimo, but spread around the warm core ring (WCR) 93A by April 10. East of the WCR93A, high Chl concentration
remained steady until May, but to the west of the WCR93A, Chl decreased rapidly before the 19th of April. From this observation
we suspect that the peak flux observed at the end of April originated from a bloom, which ceased on the 17th or 18th of April,
in the region north of 40°N and west of 143°E. Taking the current meter records into account, the source region for the trapped
material is most likely around southwest of the Cape Erimo. 相似文献
125.
啤麦穗粒结构的分阶段气候评价和预报方法研究 总被引:9,自引:0,他引:9
通过对十多年来啤麦穗粒结构与气象条件的关系的计算分析,得出了啤麦不同生育阶段影响穗粒结构的主要气象要素,并建立起其间的线性关系模式,为对啤麦产量构成要素进行分阶段的气候评价和预报提供了新的方法。 相似文献
126.
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128.
The persistence effect contribution of legacy nutrients is often cited as a reason for little or no improvement in water quality following extensive implementation of watershed nutrient mitigation actions, yet there is limited knowledge concerning factors influencing this response, often called the “persistence effect.” Here, we adopted detrended fluctuation analysis and Spearman analysis methods to assess the influence of land use on the watershed phosphorus (P) persistence effect, using monthly water quality records during 2010–2016 in 13 catchments within a drinking water reservoir watershed in eastern China. Detrended fluctuation analysis was used to calculate the Hurst exponent α to assess watershed legacy P characteristics (α ≈ 0.5, α > 0.5, and α < 0.5 indicate white noise, persistence, and anti‐persistence, respectively). Results showed weak to strong P persistence (0.60–0.81) in the time series of riverine P in the 13 catchments. The Hurst exponent α had negative relationships with agricultural land (R = ?.47, p = .11) and developed land (R = ?.67, p = .01) and a positive relationship with forest land cover (R = .48, p = .10). The persistence effect of riverine P was mainly determined by retention ability (biogeochemical legacy) and migration efficiency (hydrological legacy). A catchment with strong retention capacity (e.g., biomass uptake/storage and soil PO4 sorption) and low migration efficiency results in a stronger persistence effect for riverine P. In practice, source control is more effective in catchments with weak persistence, whereas sink control (e.g., riparian buffers and wetlands) is preferred in catchments with strong persistence effects. 相似文献
129.
P phase arrival picking of weak signals is still challenging in seismology. A wavelet denoising is proposed to enhance seismic P phase arrival picking, and the kurtosis picker is applied on the wavelet-denoised signal to identify P phase arrival. It has been called the WD-K picker. The WD-K picker, which is different from those traditional wavelet-based pickers on the basis of a single wavelet component or certain main wavelet components, takes full advantage of the reconstruction of main detail wavelet components and the approximate wavelet component. The proposed WD-K picker considers more wavelet components and presents a better P phase arrival feature. The WD-K picker has been evaluated on 500 micro-seismic signals recorded in the Chinese Yongshaba mine. The comparison between the WD-K pickings and manual pickings shows the good picking accuracy of the WD-K picker. Furthermore, the WD-K picking performance has been compared with the main detail wavelet component combining-based kurtosis (WDC-K) picker, the single wavelet component-based kurtosis (SW-K) picker, and certain main wavelet component-based maximum kurtosis (MMW-K) picker. The comparison has demonstrated that the WD-K picker has better picking accuracy than the other three-wavelet and kurtosis-based pickers, thus showing the enhanced ability of wavelet denoising. 相似文献
130.
构造叠加晕找盲矿法是在原生晕找盲矿法理论基础上发展的新技术方法。根据热液矿床成矿成晕具多期多阶段叠加特点提出的原生晕叠加理论,将原生晕找盲矿法发展为原生叠加晕找盲矿法;根据热液矿床成矿成晕严格受构造控制而提出的构造叠加晕理论,将原生叠加晕找盲矿法发展为构造叠加晕找盲矿法。文章介绍了从原生晕到原生叠加晕又到构造叠加晕找盲矿法在理论、研究思路、工作方法等方面的发展与创新。 相似文献