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51.
图像配准和融合及其在医学影像中的应用 总被引:2,自引:2,他引:2
图像配准和融合是图像分析和处理的基本问题,在医学影像、遥感、计算机视觉等领域有着广泛的应用。本文研究它们在多模态医学影像技术中的应用。本文提出并实现了基于Fourier变换的图像配准和基于子波变换的图像融合方法,在图像融合中,我们采用特征选择的取大原则,这种准则更适合于来自不同图像中的明显特征 相似文献
52.
在分散度不同的区域内进行区域采样用于水中硫酸根离子的测定,结果令人满意。应用此方法测定硫酸根离子的线性范围为200.0~3000mg/L;进样频率为120次/h;相对标准偏差为1.70% 相似文献
53.
提出用VS-Ⅱ型强碱性阴离子交换纤维定量富集、硫脲解脱,流动注射在线分离富集—火焰原子吸收光谱法测定地质样品中痕量金银的分析方法。该方法检出限低,金为1.4μg/mL,银为0.35μg/mL,相对标准偏差均小于2%,采样频率为120次/h,用于地质样品中痕量金银的直接测定,结果令人满意。 相似文献
54.
南方海相油气勘探为什么久攻不下? 总被引:7,自引:0,他引:7
中国南方从震旦纪到三叠纪8个地质时代海相地层厚度巨大,具有很大的生烃能力。然而除四川地区之外,至今油气勘探尚无重大突破。积十二年对南方5个地质时代海相地层基础地质研究及制图的经验,认为南方海相油气勘探久攻不下的原因是:(1)对整个南方还缺乏全面的、历史的,整体的和深刻的认识;(2)还不于用什么方法或顺序去认识它。建议重视基础地质研究,并以中国南方二叠纪及三叠纪的岩相古地理研究和制图为例,提出基础地 相似文献
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The central difference method (CDM) that is explicit for pseudo‐dynamic testing is also believed to be explicit for real‐time substructure testing (RST). However, to obtain the correct velocity dependent restoring force of the physical substructure being tested, the target velocity is required to be calculated as well as the displacement. The standard CDM provides only explicit target displacement but not explicit target velocity. This paper investigates the required modification of the standard central difference method when applied to RST and analyzes the stability and accuracy of the modified CDM for RST. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
59.
The swing of the main channel of the Qiantang River is controlled by the high-water and low-water changes in the river, as well as the impact of large-scale reclamation of tidal flats. Its evolution in modern times is the result of the combined functions of natural and man-made factors. This paper analyzes the cause of the formation of the South Channel and Xisan Tidal Furrow and proposes the regulation principle of “To regulate the river and reclaim tidal flats by taking the advantage of local topography”. It is suggested to cut off the South Channel and Xisan Tidal Furrow completely to restrict the swing of the main channel and to increase the reclamation area of the tidal flat at the same time. 相似文献
60.
Peatland initiation and carbon dynamics in northeast China: links to Holocene climate variability 下载免费PDF全文
Wei Xing Kunshan Bao Wenyong Guo Xianguo Lu Guoping Wang 《Boreas: An International Journal of Quaternary Research》2015,44(3):575-587
Throughout northeast China, the widely distributed peatlands have formed a large carbon (C) pool. However, the relationship between peatland initiation and climate controls is still poorly documented and understood. Understanding the responses of these C‐rich ecosystems to past climate change will provide useful insights into projecting the fate of peatland C in the future. In this study, we present a detailed historical reconstruction of peatland development in northeast China based on 312 basal peat dates, and examine the relationship between Holocene peatland dynamics and climate sensitivity. Our results indicate that peatland initiation started in the early Holocene, and that the majority of peatlands were initiated by and developed during the late Holocene. After the most intensive initiation period of 4.2–0.8 ka, the rate of peatland development slowed, which was concomitant with decreasing insolation and monsoon intensity. The widespread peatland initiation in the late Holocene might have been caused by the cool and moist climate patterns. The optimum timing of the peatland development was not uniform across northeast China, and these spatio‐temporal differences indicate the influences of regional climate and terrain on peatland initiation. Peat‐core data show variations in the long‐term apparent rate of C accumulation (LORCA) during the Holocene, with an average rate of 37.2 g C m?2 a?1. The peak LORCA occurred during 10.5–9.0 ka, probably in response to higher temperatures and stronger East Asia summer monsoon intensities. Both temperature and humidity are important factors influencing the peatland initiation and C dynamics in this region. 相似文献