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101.
Analysis of multi-dimensional SAR for determining the thickness of thin sea ice in the Bohai Sea 总被引:1,自引:0,他引:1
Flat thin ice (<30 cm thick) is a common ice type in the Bohai Sea, China. Ice thickness detection is important to offshore exploration and marine transport in winter. Synthetic aperture radar (SAR) can be used to acquire sea ice data in all weather conditions, and it is a useful tool for monitoring sea ice conditions. In this paper, we combine a multi-layered sea ice electromagnetic (EM) scattering model with a sea ice thermodynamic model to assess the determination of the thickness of flat thin ice in the Bohai Sea using SAR at different frequencies, polarization, and incidence angles. Our modeling studies suggest that co-polarization backscattering coefficients and the co-polarized ratio can be used to retrieve the thickness of flat thin ice from C- and X-band SAR, while the co-polarized correlation coefficient can be used to retrieve flat thin ice thickness from L-, C-, and X-band SAR. Importantly, small or moderate incidence angles should be chosen to avoid the effect of speckle noise. 相似文献
102.
103.
利用NSIDC公布的ICESat运行期间的19个任务期的观测数据, 采用重复轨迹分析方法估计近年来南极冰盖高程的时空变化。结果表明,南极大陆冰盖整体上呈现消融趋势,基于不同的GIA模型和ICESat激光测高数据的南极大陆冰盖高程变化的趋势约为 -1.17~-1 cm/a。 相似文献
104.
CryoSat-2卫星海冰区域波形识别及海冰干舷高确定 总被引:1,自引:0,他引:1
利用40%阈值法对CryoSat-2卫星波形数据进行重跟踪,将波形特征参数和海冰浓度相结合,对海冰和Lead(浮冰之间的开阔水域)进行有效识别。利用沿轨前后搜索算法计算海冰干舷高,并引用AWI结果,绘制2011~2013年北冰洋多年冰区域和一年冰区域平均海冰干舷高变化趋势图。比较本文结果与AWI结果的各年同期数据,验证本文结果的可靠性。 相似文献
105.
Yingchun Lv Rong Zheng Tao Zuo Yuming Wang Zhaojie Li Yong Xue Changhu Xue Qingjuan Tang 《中国海洋大学学报(英文版)》2014,13(5):825-829
Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene (COI) was used to identifing five sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible. 相似文献
106.
刘思俭 《广东海洋大学学报》1995,(2)
综述了我国及广东省十多年来鱼虾种苗人工放流及人工鱼礁的投放情况,结合广东省广大海区的水温、盐度、pH值、海流、营养盐含量情况及天然饵料的种类、分布等,提出了除在大亚湾已设置了水产增殖站以外,还应该在广东东部的南澳和西部的湛江各设一个增殖站,会收到更大的效果。人工鱼礁应总结过去投放的经验,加强礁区管理,逐步解决投资与收益的关系问题,并进一步扩大投放人工鱼礁的地点和密度,把广东海区切实建成理想的海洋牧场。 相似文献
107.
The effects of recombinant eel growth hormone (reGH).methyltestosterone (MT)and L-thyroxine (T4)on the growth of red sea bream. Pagrosomus major.were investigated.Administration of reGH to fry by immersion at 2 mg 1 for 2 hevery 5 dsys resulted in significant increase in both weight and length.but the condition factor (CF) diminished relative to that of similarly treated controls over the 37day treatment period.Immersion in 0.1 mg:1 T4 also resulted in significant increase in both weight and length and higher survival rate of test fry compared to the controls. Immersion in MT had less effect on growth and high-dose resulted in high mortality.In the second study.injection of 2 μg reGH(gwk)caused a significant increase in the specific growth rate (SGR) of test red sea bream fingerlings relative to that of the controls during the 4-week treatment period and maintained the increasing trend over the post-treatment period (weeks 4-6).Injection of MT at a dosage of 1μg (gwk) resulted in a significant in-creas 相似文献
108.
张松才 《广东海洋大学学报》2002,22(5):14-20
广东近代诗歌浓郁的海洋意象与海上丝路有着密切的联系。海上丝路深刻地影响了广东近代文学 ,为之提供了丰富的创作题材和空间 ;而广东近代文学又反过来促进了海上丝路的发展和繁荣。 相似文献
109.
Changes in sea surface temperature(SST), seawater oxygen isotope(δ 18 O sw), and local salinity proxy(δ 18 O sw-ss) in the past 155 ka were studied using a sediment core(MD06-3052) from the northern edge of the western Pacifi c Warm Pool(WPWP), within the fl ow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ 18 O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO 2 profi le showed a close connection between the WPWP and the Antarctic. Values of δ 18 O sw exhibited very similar variations to those of mean ocean δ 18 O sw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ 18 O sw-ss refl ect a more saline condition during high local summer insolation(SI) periods. Such correspondence between δ 18 O sw-ss and local SI in the WPWP may refl ect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their infl uence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP. 相似文献
110.
Stress Responses to Rapid Temperature Changes of the Juvenile Sea Cucumber (Apostichopusjaponicus Selenka) 总被引:2,自引:0,他引:2
DONG Yunwei JI Tingting DONG Shuanglin 《中国海洋大学学报(英文版)》2007,6(3):275-280
Activities of hexokinase (HK), pyruvate kinase (PK), superoxide dismutase (SOD) and catalase (CAT) and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber (Apostichopus japonicus Selenka) to rapid temperature changes in laboratory. Animals were subjected to a higher temperature (from 10 to 20℃) (Tinc treatment) or to a lower temperature (from 20 to 10℃) (Tddec treatment) for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment. 相似文献