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911.
912.
This paper proposes a scheme for detecting the swell decay of a moving typhoon. We considered a typhoon that was neither far from a point source nor had a belt-like homogenous source,as previously studied. We tracked the swell close to the source during a typhoon in the western North Pacific Ocean. We used wind speed and significant wave height data derived from the Geophysical Data Record of the Jason-1 altimeter and the best-track information of the typhoon from the China Meteorological Administration tropical cyclone database. We selected three specific cases to reveal the decay characteristics of the swell generated by a moving typhoon. Based on an altimeter-based typhoon swell identification scheme and the dispersion relationship for deep water,we relocated the swell source for each altimeter measurement. The subsequent statistical decay coefficient was comparable to previous studies,and effectively depicted the swell propagation conditions induced by the typhoon. We hope that our results provide a new understanding of the characteristics and wave energy budget of the North Pacific Ocean,and significantly contribute to wave modeling in this region. 相似文献
913.
????й????????????λ??????????????GNSS????????????????????????????????????GPS?????????????????,??????÷????????????????????????????????????????????????????IGS???????????????????????????£??????й??????????????????????????÷???????Ч????????? 相似文献
914.
Tang Guo'an Ge Shanshan Li Fayuan Zhou Jieyu 《山地科学学报》2005,2(3):265-270
Introduction The Loess Plateau is located in the upper and middle reaches of the Yellow River, among the western Taihang Mt, eastern Riyue-Helan Mt, northern Qinling Mt, and southern Yinsan Mt (from 100°54′to 114°33′E and 33°43′to 41°31′N; Figure 1). It covers a total area of 624,000 km2. The Loess Plateau of China has drawnworldwide attention in geographical research for its unique morphological features, abundant nature resources, most serious soil erosion, as well as its pot… 相似文献
915.
The estimation of gear selectivity is a critical issue in fishery stock assessment and management. Several methods have been
developed for estimating gillnet selectivity, but they all have their limitations, such as inappropriate objective function
in data fitting, lack of unique estimates due to the difficulty in finding global minima in minimization, biased estimates
due to outliers, and estimations of selectivity being influenced by the predetermined selectivity functions. In this study,
we develop a new algorithm that can overcome the above-mentioned problems in estimating the gillnet selectivity. The proposed
algorithms include minimizing the sum of squared vertical distances between two adjacent points and minimizing the weighted
sum of squared vertical distances between two adjacent points in the presence of outliers. According to the estimated gillnet
selectivity curve, the selectivity function can also be determined. This study suggests that the proposed algorithm is not
sensitive to outliers in selectivity data and improves on the previous methods in estimating gillnet selectivity and relative
population density of fish when a gillnet is used as a sampling tool. We suggest the proposed approach be used in estimating
gillnet selectivity. 相似文献
916.
Cultivable magnetotactic bacteria (MTB) in laboratory can provide sufficient samples for molecular microbiological and magnetic
studies. However, a cold-stored MTB strain, such as Magnetospirillum magneticum AMB-1, often loses its ability to synthesize magnetosomes and consequently fails to sense the external magnetic field. It
is therefore important to quickly recover vigorous bacteria cells that highly capable of magnetosome producing. In this study,
a modified capillary magnetic separation system was designed to recover a deteriorating strain of Magnetospirillum magneticum AMB-1 that long-term cold-stored in a refrigerator. The results show that all cells obtained after a 3-cycle treatment were
vigorous and had the ability to produce magnetosomes. Moreover, the 3rd-cycle recovered cells were able to form more magnetosome crystals. Compared with the colony formation method, this new method
is time-saving, easily operated, and more efficient for recovering vigorous MTB cells. 相似文献
917.
????????????У?????????λ???α??????С??·??Ч???α??????????????????е????????????????????????????α??????????????????·??Ч????????????α?????λ???????????????????????λ???α??????????????????????÷??????????????????????λ????? 相似文献
918.
介绍了气象知识多媒体演示系统的总体设体、实施方案及在具体实现过程中的主要技术方法 相似文献
919.
中国大陆西部地区现今的块体运动 总被引:1,自引:0,他引:1
根据中国地壳运动GPS监测网1992~1996年3次复测结果,分析了我国大陆西部地区现今块体运动的基本特征,结果表明:印度板块向北推挤是我国西部块体褶皱运动和变形的根源;由於内部次级断块的边界条件和受力方式不同,块体边界和内部构造形变亦具有明显的差异。块体运动主要特点表现为:(1)喜马拉雅向南弯曲的弧形边界东西两端,印度板块推挤运动方向不同,导致了弧前方的亚板块和构造块体的运动方向呈扇形散开;(2)青藏高原主体在南北向缩短、东西向延伸的同时存在着明显向东的物质侧向滑移;(3)重要块体分界带和褶皱带两侧运动矢量的比较表明,阿尔金断裂为左旋走滑,天山、祁连山均呈压性;(4)由设置在不同块体的GPS测站南北向和东西向运动速率及速率的平均值得到的块体运动速率和方向,呈有规则的变化,其变化规律与地质、地球物理结果具有较好的一致性。 相似文献
920.
本文论述了环境地球物理学的缘起及产生的科学背景、技术背景和应用背景 ,阐述了有关环境地球物理学的概念、研究内容以及主要方法技术 ,并指出其工作重点和发展方向。最后 ,展望了其发展前景 ,并提出几点想法 相似文献