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复数,实数及实对称数据下Bruun FFT算法的实现   总被引:3,自引:0,他引:3  
本文在复数、实数以及实对称数据下研究和实现了Bruun FFT算法。文章分析和评价了各种数据下BruunFFT的运算量和特点,提出了算法的实现结构和方法。最后给了TMS320C30上的运算时间,我们实现的算法比基2FFT速度提高35%。  相似文献   
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Ravelo AC  Andreasen DH  Lyle M  Olivarez Lyle A  Wara MW 《Nature》2004,429(6989):263-267
The Earth's climate has undergone a global transition over the past four million years, from warm conditions with global surface temperatures about 3 degrees C warmer than today, smaller ice sheets and higher sea levels to the current cooler conditions. Tectonic changes and their influence on ocean heat transport have been suggested as forcing factors for that transition, including the onset of significant Northern Hemisphere glaciation approximately 2.75 million years ago, but the ultimate causes for the climatic changes are still under debate. Here we compare climate records from high latitudes, subtropical regions and the tropics, indicating that the onset of large glacial/interglacial cycles did not coincide with a specific climate reorganization event at lower latitudes. The regional differences in the timing of cooling imply that global cooling was a gradual process, rather than the response to a single threshold or episodic event as previously suggested. We also find that high-latitude climate sensitivity to variations in solar heating increased gradually, culminating after cool tropical and subtropical upwelling conditions were established two million years ago. Our results suggest that mean low-latitude climate conditions can significantly influence global climate feedbacks.  相似文献   
3.
西部农业信息化建设问题的探讨   总被引:3,自引:0,他引:3  
西部农业信息化水平低下制约着西部农业的发展。物质基础薄弱、信息意识淡薄、信息人才及资金短缺是造成西部农业信息化水平低下的原因。为加快西部信息化农业建设,应该从更新观念、加大政府支持力度、利用有限资源进行信息化基础建设、重视人才资源的开发、培育信息产品市场、加强农业应用系统和信息化农业技术的研究、加强示范应用体系等方面入手。  相似文献   
4.
The plasminogen activation system in tumor growth, invasion, and metastasis   总被引:61,自引:0,他引:61  
Generation of the serine proteinase plasmin from the extracellular zymogen plasminogen can be catalyzed by either of two other serine proteinases, the urokinase- and tissue-type plasminogen activators (uPA and tPA). The plasminogen activation system also includes the serpins PAI-1 and PAI-2, and the uPA receptor (uPAR). Many findings, gathered over several decades, strongly suggest an important and causal role for uPA-catalyzed plasmin generation in cancer cell invasion through the extracellular matrix. Recent evidence suggests that the uPA system is also involved in cancer cell-directed tissue remodeling. Moreover, the system also supports cell migration and invasion by plasmin-independent mechanisms, including multiple interactions between uPA, uPAR, PAI-1, extracellular matrix proteins, integrins, endocytosis receptors, and growth factors. These interactions seem to allow temporal and spatial reorganizations of the system during cell migration and a selective degradation of extracellular matrix proteins during invasion. The increased knowledge about the plasminogen activation system may allow utilization of its components as targets for anti-invasive therapy.  相似文献   
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引入研究型大学及其图书馆的定义,阐述了研究型大学图书馆进行人力资源管理的重要意义。进而提出了研究型大学图书馆人力资源管理的策略,包括改变人力资源管理理念,建立以人为本的人才管理机制,注重人才的使用和培养,充分调动馆员的积极性等。  相似文献   
6.
人才是提高综合国力的关键要素。为用好人才,一是要辨证地把握好识别人才、起用人才的标准,既要选拔出德才兼备的人才,又不可求全责备;二是用人要讲究方法。做到公平竞争、择优录用、知人善用,同时鼓励人才合理流动;三是用人要遵循讲正气、讲民主、讲大度的原则,大胆使用人才。  相似文献   
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