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271.
黑体辐射反问题就是利用测量的黑体辐射能量谱确定黑体的区域温度分布.本文将该问题离散化为欠定线性不适定问题,提出求解欠定线性不适定问题的正则化Lanczos方法.该方法基于Lanczos双对角化过程,用一系列小型线性方程组逼近原不适定问题,应用截断SVD正则化方法使迭代稳定化,并用L-曲线确定相应的正则化参数.数值结果说明了新方法的有效性,并说明了在观测数据出现误差的情况下新方法也能有效地重构区域温度分布.  相似文献   
272.
传统的基于物理样机的研制方法开发周期长、费用高,极大的制约了遥感器的研制和应用.遥感器的研制过程可以抽象成为信息在市场、设计、生产各个部门之间的收集、处理、应用的过程.虚拟样机是产品的数字模型的集合,是记录信息的载体以及应用信息的工具,能够表达产品各个方面的特性.可以对遥感器的全生命周期提供支持.文章提出了基于虚拟样机的遥感器设计、分析、制造一体化思想,分析了其关键支撑技术,并给出了一个基于虚拟样机的遥感器性能分析应用实例.  相似文献   
273.
274.
In order to obtain deformation parameters in each block of Sichuan-Yunnan Region (SYG) in China by stages and establish a dynamic model about the variation of the strain rate fields and the surface expansion in this area, we taken the Global Positioning System (GPS) sites velocity in the region as constrained condition and taken advantage of the block strain calculation model based on spherical surface. We also analyzed the deformation of the active blocks in the whole SYG before and after the Wenchuan earthquake, and analyzed the deformation of active blocks near the epicenter of the Wenchuan earthquake in detail. The results show that, (1) Under the effects of the carving from India plate and the crimping from the potential energy of Tibetan Plateau for a long time, there is a certain periodicity in crustal deformation in SYG. And the period change and the earthquake occurrence have a good agreement. (2) The differences in GPS velocity fields relative Eurasian reference frame shows that the Wenchuan earthquake and the Ya'an earthquake mainly affect the crustal movement in the central and southern part of SYG, and the average velocity difference is about 4–8?mm/a for the Wenchuan earthquake and 2–4?mm/a for the Ya'an earthquake. (3) For the Wenchuan earthquake, the average strain changed from 10 to 20 nanostrian/a before earthquake to 40–50 nanostrian/a after the earthquake, but before and after the Ya’an earthquake, the strain value increased from about 15 nanostrian/a to about 30 nanostrian/a. (4) The Wenchuan earthquake has changed the strain parameter of each active block more or less. Especially, the Longmen block and Chengdu block near the epicenter. The research provides fundamental material for the study of the dynamic mechanism of the push extrusion from the north-east of the India plate and the crimp from Qinghai Tibet Plateau, and it also provides support for the study of crustal stress variation and earthquake prediction in Sichuan Yunnan region.  相似文献   
275.
The design and operation of a high altitude scientific balloon requires adequate knowledge of the thermal characteristics of the balloon to make it safe and reliable. The thermal models and dynamic models of altitude scientific balloons are established in this paper. Based on the models, a simulation program is developed. The thermal performances of a super pressure balloon are simulated. The influence of film radiation property and clouds on balloon thermal behaviors is discussed in detail. The results are helpful for the design and operate of safe and reliable high altitude scientific balloons.  相似文献   
276.
A tethered aerostat may break away due to the cable damage caused by abrasion or strong wind. In order to avoid losing the aerostat, the discharge valve will open automatically when the aerostat escapes into the air. It is necessary to know its breakaway characteristics because it is different from those of the launch process. This work develops the dynamic and thermal models for tethered aerostat breakaway characteristics with the finite difference method. Based on the developed models, a computer program in FORTRAN is developed. Then, the program is used to simulate tethered aerostat breakaway characteristics, including ascent and descent behaviors, flight altitude, flight duration, and the influence of the discharge valve characteristics, ascent velocity and hull volume on the hull overpressure. The simulation results are helpful for better understanding tethered aerostat breakaway characteristics and for developing tethered aerostat breakaway control strategies and systems.  相似文献   
277.
星箭分离后末级火箭的爆炸造成大量的空间碎片,严重威胁载人航天等空间活动。解决措施之一就是末级火箭剩余燃料的排放。星箭分离后遥测数据处理的目的是监测分析末级火箭推进剂的排放过程。文中讨论星箭分离后火箭遥测数据的基本特点、星箭分离后火箭遥测数据处理软件各模块的主要功能,以及软件在实现过程中采用的关键技术,并对遥测处理结果数据的分析和拓展应用进行了阐述。  相似文献   
278.
基于县级数据的机场人口覆盖率测算方法及结果差异   总被引:2,自引:0,他引:2  
机场可达性是机场建设和规划的重要指标。本文讨论了可达性研究中的参数设置与计算方法,并采用我国2009年县级数据计算和对比了不同方法得到的机场人口覆盖率。结果发现不同方法得到的结果存在较大差异,所反映的机场服务水平的空间格局也有差异。本文进一步讨论了其对机场规划的启示。  相似文献   
279.
Kinesin and kinesin-like proteins (KLPs) constitute a superfamily of microtubule motor proteins found in all eukaryotic organisms. Members of the kinesin superfamily are known to play important roles in many fundamental cellular and developmental processes. To date, few published studies have reported on the effects of microgravity on kinesin expression. In this paper, we describe the expression pattern and microgravity-sensitive genes of kinesin in rat bone marrow stromal cells cultured in a ground-based rotating bioreactor. The quantity of kinesin under the clinorotation condition was examined by immunoblot analysis with anti-kinesin. Furthermore, the distribution of kinesin at various times during clinorotation was determined by dual immunostaining, using anti-kinesin monoclonal antibody or anti-β-tubulin monoclonal antibody. In terms of kinesin quantity, we found that the ratios of the amounts of clinorotated/stationary KLPs decreased from clinorotation day 5 to day 10, although it increased on days 2 and 3. Immunofluorescence analysis revealed that kinesin in the nucleus was the first to be affected by simulated microgravity, following the kinesin at the periphery that was affected at various times during clinorotation. Real-time RT-PCR analysis of kinesin mRNA expression was performed and led to the identification of 3 microgravity-sensitive kinesin genes: KIF9, KIFC1, and KIF21A. Our results suggest that kinesin has a distinct expression pattern, and the identification of microgravity-sensitive kinesin genes offers insight into fundamental cell biology.  相似文献   
280.
本文建造了一个地理信息系统的模型,并讨论了地理信息系统设计中的一些关键技术。  相似文献   
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