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91.
92.
The Transylvanian Basin is a mature hydrocarbon province of Romania characterized by two petroleum systems: Mesozoic (thermogenic) and Miocene (biogenic). An extensive outcrop-based sedimentological and micropaleontological study correlated to seismic and well data discusses the elements of the Miocene petroleum system. The facies associations are indicative of alluvial, fandelta, shallow- and deep-marine settings. These are grouped into four different depositional systems (evaporite, mud-carbonate, sand-mud and sand-gravel). Their evolution in time and space shows large differences between various parts of the basin that have important consequences for exploration. 相似文献
93.
Primary productivity (PP) and phytoplankton structure play an important role in regulating oceanic carbon cycle. The unique seasonal circulation and upwelling pattern of the South China Sea (SCS) provide an ideal natural laboratory to study the response of nutrients and phytoplankton dynamics to climate variation. In this study, we used a three-dimensional (3D) physical–biogeochemical coupled model to simulate nutrients, phytoplankton biomass, PP, and functional groups in the SCS from 1958 to 2009. The modeled results showed that the annual mean carbon composition of small phytoplankton, diatoms, and coccolithophores was 33.7, 52.7, and 13.6 %, respectively. Diatoms showed a higher seasonal variability than small phytoplankton and coccolithophores. Diatoms were abundant during winter in most areas of the SCS except for the offshore of southeastern Vietnam, where diatom blooms occurred in both summer and winter. Higher values of small phytoplankton and coccolithophores occurred mostly in summer. Our modeled results indicated that the seasonal variability of PP was driven by the East Asian Monsoon. The northeast winter monsoon results in more nutrients in the offshore area of the northwestern Luzon Island and the Sunda Shelf, while the southwest summer monsoon drives coastal upwelling to bring sufficient nutrients to the offshore area of southeastern Vietnam. The modeled PP was correlated with El Niño/Southern Oscillation (ENSO) at the interannual scale. The positive phase of ENSO (El Niño conditions) corresponded to lower PP and the negative phase of ENSO (La Niña conditions) corresponded to higher PP. 相似文献
94.
Haiqing Ma ;Qian Song ;Xuchen Wang 《海洋湖沼学报（英文）》2009,27(4):887-897
Accumulation and distributions of aliphatic and polyaromatic hydrocarbons (PAHs) and heavy metals were measured in tissues of the clam Ruditapes philippinarum collected from 5 sites in Jiaozhou Bay, Qingdao, China. The concentrations of total aliphatic hydrocarbon and PAHs ranged from 570 to 2 574 ng/gdw (gram dry weight) and from 276 to 939 ng/gdw, in the most and least polluted sites, respectively. The bio-accumulation of hydrocarbons and PAHs in the clams appeared to be selective. Aliphatic hydrocarbons were predominantly represented by short chain ( 相似文献
95.
Yuxiang Ma Guohai Dong Marc Perlin Shuxue Liu Jun Zang Yiyan Sun 《Ocean Engineering》2009,36(8):595-604
This paper considers higher-harmonic forces due to wave focusing on a vertical circular cylinder. A series of experiments has been conducted in a wave flume. The first six-harmonic components of the measured wave forces are analyzed using the scale-averaged wavelet spectrum. It is noted that due to the transient nature of focused (freak) waves, Fourier analysis would not provide equivalent information to that gleaned from the analyses used herein. The results for the experiments with very steep wave crests show significant amplitudes at the fourth and fifth harmonics. These harmonics exhibit amplitudes that are the same order as the second harmonic, but much larger than those of the third harmonic. The wavelet-based bicoherence is used to detect the quadratic nonlinearity of the measured forces. And the bicoherence spectra reveal the primary mathematical reason for the existence of the striking amplitudes of the fourth and fifth harmonics: the interaction between the lower-harmonic components couple more strongly with the fourth and fifth harmonics, thus the fourth and fifth harmonics glean more energy than those of the third-harmonic components. However, the physical explanation for this remains elusive. 相似文献
96.
Xinan Wang ;Aijun Ma 《海洋湖沼学报（英文）》2009,27(4):708-713
We conducted behavior experiments on the roles of vision, olfaction, and the lateral line in feeding in tongue sole Cynoglossus semilaevis Günter. Chemical cues from the prey alone could not elicit any searching or attacking behavior by the fish; only when moving foods were presented, the chemical nature of the foods affected feeding. In addition, we found that normal tongue sole did not accurately recognize moving artificial prey of different shapes. Neither chemosense nor vision plays an important role in prey detection. Reactions to moving objects and the response of the oropharyngeal cavity to different foods showed that the (eyeless) tongue sole use mainly the lateral line for prey detection and capture. Gustation in the oropharyngeal cavity is essential for the fish to swallow its prey. 相似文献
97.
Jizhen Ma ;Xinqiang Shen ;Qi Yuan ;Mei Jiang 《海洋湖沼学报（英文）》2008,26(4):388-393
To analyze and evaluate the status of organochlorine pollutants in the Changjiang (Yangtze River) estuary and adjacent waters, the concentrations of hexachlorocyclohexane (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in shellfish collected in study area from 2006 to 2007 were determined with gas chromatography (GC). The concentration range of HCHs was (ND-12.13)×10−3 mg/kg wet weight and averaged at 0.54×10−3 mg/kg while the concentration of DDTs was in the range of (4.06–281.73) ×10−3 mg/kg with a mean of 57.52×10−3 mg/kg in the survey areas. The concentrations of DDTs in the shellfish were higher than HCHs’, so that DDTs could be considered as typical organochlorine pollutants in the areas. The concentrations of DDTs in the shellfish were higher than HCHs’, so that DDTs could be considered as typical organochlorines pollutants. The HCHs in all the shellfish conformed to the first level of criterion (0.02 mg/kg) of the Marion Biology Quality (GB 18421-2001), and that of DDTs in most samples were beyond the first level (0.01 mg/kg) but conformed to the second level (0.10 mg/kg). On average, α-HCH and δ-HCH occupied the most part of HCHs, while O,P’-DDT and P,P’-DDT occupied the most part of DDTs. The concentrations of organocholorine pesticides in shellfish samples varied in site and in species. The highest level occurred at the Shengsi (SS), followed by Yangkougang (YKG), Lvsi (LS), Dongyuan (DY) and Beibayao (BBY), low concentrations were observed at Changsha (CS), Beidaodi (BDD), and Gouqi (GQ). The concentration of HCHs and DDTs in most sites decreased clearly from 2006 to 2007 except for YKG, DY, BDD, LYS, and SS. All of above results suggested that the study area was slightly affected by organochlorine pesticide, special by DDTs. 相似文献
98.
潟湖是重要的海岸湿地类型,具有丰富的自然资源和独特的生态功能。近几十年来,我国的海岸潟湖遭到了极大破坏,因此,开展我国海岸潟湖遥感监测与分析具有重要意义。本文根据1979年、1990年、2000年和2010年的4期共102景多时相遥感影像数据,利用遥感和地理信息系统等技术方法对我国大陆海岸潟湖进行了遥感监测,首次调查统计了我国大陆海岸潟湖的名称、数量、分布、岸线长度和面积信息,并对近31年来我国大陆海岸潟湖的变迁状况进行了分析。结果表明,1979年我国大陆海岸潟湖共计251个,近31年,共消失19个潟湖,其中辽宁省消失15个,广东省消失3个,广西壮族自治区消失1个;1979年我国大陆海岸潟湖岸线总长度为2 692.26km,总面积为1 092.805 5km2,至2010年我国大陆海岸潟湖岸线总长度共减少337.80km,潟湖总面积共减少204.103km2;31年间,我国大陆海岸潟湖的岸线长度和潟湖面积总体均处在持续减少的状态,各省(自治区)也基本符合该规律;1979-2010年间,我国大陆海岸潟湖大部分处在老年期,死亡期潟湖消失19个。 相似文献
99.
碱蓬和柽柳是黄河口湿地典型的盐生植物类型,是多种保护珍禽的主要栖息地,具有景观尺度较小、分布广且多混生的特点。应用覆盖黄河口北部潮滩的HJ-1A高光谱遥感影像,基于现场测量的端元光谱和从遥感影像中使用顺序最大角凸锥法(SAMCC)自动提取的端元光谱,应用线性光谱分解法(LSU)、正交子空间投影法(OSP)、匹配滤波法(MF)、最小能量约束法(CEM)和自适应一致估计法(ACE)5种不同光谱解混方法进行混合像元光谱解混,对比两种方法得到的端元光谱分别对碱蓬和柽柳盖度的反演能力,并给出相应的反演模型。结果显示:(1)现场测量端元光谱取得了较好的碱蓬和柽柳盖度反演结果,其中应用LSU方法的光谱解混结果与现场测量盖度的决定系数对于碱蓬和柽柳分别达到了0.88和0.95;(2)两种端元获取方式的光谱解混结果中,LSU和OSP方法均获得了较高的相关性,ACE解混方法的相关性都最低;(3)SAMCC方法提取端元光谱对柽柳的分解结果与现场测量盖度的相关性远高于碱蓬。 相似文献
100.
依托国家重点基础研究（973）计划项目\"上层海洋对台风的响应和调制机理研究\",中国气象局上海台风研究所联合国家海洋局的相关单位,通过实施近海台风的外场观测科学试验、加强台风边界层（特别是海气相互作用）物理过程诊断分析及参数化方案等的研究,建立并改进了台风强度预报的海-气-浪耦合预报模式系统,并在此基础上发展了台风强度的集合预报技术,在历史典型台风个例和2016-2017年台汛期的业务化测试中表现出良好的预报性能。 相似文献