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41.
提出了保持质量体系有效运行的前提和基础 ,关键和保证措施 ,并指出了组织企业保持质量体系持续有效的方法和途径。  相似文献   
42.
通过对影响能见度的因素的分析,提出了一种能见度预报方法-综合分析法,极大地提高了能见度的预报准确率。  相似文献   
43.
THECONSTRUCTIONANDITSDEVELOPMENTOFTHEOVERSEASTRANSPORTSYSTEMINNORTHEASTCHINAGaoShali(高莎丽)(DepartmentofGeography,NortheastNorm...  相似文献   
44.
The sand–loess transition zone in north China is sensitive to climate change, and is an ideal place to investigate past environmental changes. However, past climate change at millennial–centennial timescales in this region has not been well reconstructed because of limited numerical dating. Alternations of sandy loam soils with aeolian sand layers in the Mu Us and Otindag sand fields, which lie along the sand–loess transition zone, indicate multiple intervals of dune activity and stability. This change is probably a response to variations of the East Asian monsoon climate during the late Quaternary. The single aliquot regeneration (SAR) optically stimulated luminescence (OSL) dating protocol, which has been successfully applied to aeolian deposits worldwide, is applied to these two sand fields in this study. The OSL ages provide reliable constraints for reconstruction of past climate changes at suborbital timescale. Sections in both sand fields contain aeolian sand beds recording millennial‐scale episodes of dry climate and widespread dune activation, including episodes at about the same time as Heinrich Event 5 and the Younger Dryas in the North Atlantic region. These results demonstrate the potential of aeolian sediments in semi‐arid north China to record millennial‐scale climatic events, and also suggest that dry–wet climate variation at the desert margin in China may be linked to climatic change elsewhere in the Northern Hemisphere, through atmospheric circulation. This article was published online on 27 November 2008. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected (16 December 2008). Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
45.
We consider orbital resonances in multiplanet systems. These are expected to arise during or just after formation in a gaseous disc. Disc–planet interaction naturally produces orbital migration and circularization through the action of tidal torques which in turn may lead to an orbital resonance. The mass and angular momentum content of the disc is likely to be comparable to that in the planets so that it is essential to fully incorporate the disc in the analysis.We study the orbital evolution of two planets locked in 2:1 commensurability through migration tidally induced by the disc using both analytic methods and numerical hydrodynamic simulations. The planets are assumed to orbit in an inner cavity containing at most only a small amount of disc material. Results are found to be sensitive to initial surface density profile, planet masses and disc parameters. The evolution may range between attaining and subsequently maintaining a resonance lock with two angles librating to divergent migration with no commensurability formed. In the former case eccentricities increase monotonically with time while the system undergoes inward migration. If the migration is halted by loss of the disc leaving the planets in a final configuration, there is likely to be a low probability of seeing resonant planets at small radii as well as a sensitive dependence on past history.We have also considered a multiplanet system in secular apsidal resonance. We consider the system as being in just one secular normal mode and include the effects of a gaseous disc. It is suggested that a normal mode may be selected by adding in some weak dissipative process in the disc and that it may remain, involving only the planets, when the disc is slowly removed.  相似文献   
46.
智能照明系统在现代建筑照明中的应用研究   总被引:1,自引:0,他引:1  
在对传统照明系统和智能照明系统进行对比分析的基础上,剖析了智能照明系统的控制策略,并结合实际的工程应用,着重讨论了基于ABB I-Bus产品的智能照明控制系统的实现,结果表明该系统具有高效、便捷、节约能源等优点.同时,还对系统与建筑物楼宇自控系统问的系统集成方式进行了研究.  相似文献   
47.
The Nilgiri Mountains of south India is considered unique by anthropologists, geologists, climatologists, botanists as well as tourists. It has remained a subject of constant study and research over the last two centuries. Man-nature balance had continued undisturbed in the Nilgiris for thousands of years until the early 19th century when it became a British colony attracting, in due course, various developmental activities. Subsequently, the Nilgiris and its popular hill stations emerged as favourite places for the British population in India for rest and recuperation, game and for raising commercial plantations. In the process, the traditional indigenous crops were replaced by “English“ vegetables and the natural forests gave way to commercial plantations of coffee, tea and other exotic species of trees.  相似文献   
48.
利用高光谱数据进行植被生化成分反演方法研究   总被引:3,自引:0,他引:3  
高光谱数据包含着丰富光谱信息,能够定量地分析物质成分[1]。由高光谱数据,可以运用多元逐步线性回归方法反演植被生化组分含量,从而达到监测植被生长状况的目的[2]。本文具体介绍了多元逐步线性回归方法,及其在氮、木质素和纤维素含量估算中的应用。  相似文献   
49.
首先分析了地理信息系统的组成、地理信息系统数据的特征、地理信息系统数据库的功能,然后进行了中心式导航系统数据库的设计,给出了数据库模型的E-R图,最后描述了空间地理信息的查询功能。  相似文献   
50.
LINUX,一个优秀的代码开放的操作系统。对其内核代码的分析,无论对编程或者学习操作系统原理都将事半功倍。然而处于安全性考虑,CPU的设计者将系统空间和用户空间分离,这个措施造成了对内核代码进行调试运行的困难。有许多方法可以使用户程序进入系统空间,比如中断方式、系统调用方式……我们介绍的是采用模块的方式使应用程序进入系统空间。  相似文献   
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