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61.
红外成像探测,激光成像测距的光学主被动复合导引头工作波长短,具有良好的空间分辨率和速度分辨率,可大幅度提高对RV的识别距离、末制导精度及杀伤概率。简要介绍了国外光学主被动复合导引头的研发动态,基本原理及关键技术达到的水平。提出了跟踪研究的基本思路,途径及建议。  相似文献   
62.
In order to acquire the crop-related information in Chao Phraya Basin, time-series MODIS data were used in this paper. Although the spatial resolution of MODIS data is not very high, it is still useful for detecting very large-scale phenomenon, such as changes in seasonal vegetation patterns. After the data processing a general crop-related LULC (land use and land cover) map, cropping intensity map and cropping patterns map were produced. Analysis of these maps showed that the main land use type in the study area was farmland, most of which was dominated by rice. Rice fields mostly concentrated in the flood plains and double or triple rice-cropping system was commonly employed in this area. Maize, cassava, sugarcane and other upland crops were mainly distributed in the high alluvial terraces. Because these area often have water shortage problem particularly in the dry season which can support only one crop in a year, the cropping intensity was very low. However, some upland areas can be cultivated twice a year with crops which have short growing seasons. The crop information extracted from MODIS data sets were assessed by CBERS data, statistic data and so on. It was shown that MODIS derived crop information coincided well with the statistic data at the provincial level. At the same time, crop information extracted by MODIS data sets and CBERS were compared with each other which also showed similar spatial patterns.  相似文献   
63.
高度的智力活动、大胆的涉险精神、深奥的研究内容与快活的乐天主义"哥本哈根精神"是由20世纪初丹麦的著名科学家尼耳斯·玻尔所提出的,玻尔的挚友、著名物理学家罗森菲耳德为"哥本哈根精神"下的定义是:完全自由的判断与讨论的美德。不仅如此,玻尔倡导的"平等、自由讨论和相互紧密地合作的浓厚的学术气氛",已经成为放之四海皆宜的团队工作准则。只有在他积极营造的那种"使人感到繁忙、激动、活泼、欢快、无拘无束、和蔼可亲"的气氛中,"工作者"才会是美丽的。"哥本哈根精神"完美地诠释了团队精神,它以一个成功者的姿态存在:相互的沟通配合和较为明显的责任分担,需要更为统一的思想,对目标的认同和个人牺牲。  相似文献   
64.
空中交通管理协同决策   总被引:1,自引:0,他引:1  
CDM是一种基于信息交换及政府与企业之间联合协作的理念,用于创造更为安全和更为有效的系统环境。通过信息交换,所有参与各方就能对整个系统和所有运作限制产生一个公共的态势认知,在此基础上参与各方就能协调地做出更为安全有效的决策,同时也在最大程度上满足了各个企业的商业需求。  相似文献   
65.
程惠尔  牛禄 《推进技术》2001,22(2):126-128
根据热辐射理论,分析空间发动机外向辐射会传热的基本特点,得出在地面用模型喷管-电热喷管缩比件模拟这一传热现象的必要条件为两者几何相似,壁面热流密度q以及表面黑度ε相等。可行性分析为地面模拟试验提供了科学的依据,其结论可用来指导试验。  相似文献   
66.
海参崴印象     
“海参崴气候属温带季风性海洋气候,夏季潮湿,多雾,时有台风;秋季是海参崴最好的季节,天气晴朗,阳光充足,日照时间较长,是俄罗斯旅游度假胜地之一。”  相似文献   
67.
There are extensive reports of ionospheric disturbances before the great 2008 Wenchuan earthquake, which are possibly explained by seismogenic electric field hypotheses linked with the aerosols injected in atmosphere. This paper attempts to investigate the possible change of atmospheric aerosol optical depth (AOD) associated with this earthquake by using MODIS data from both Terra and Aqua satellites. The result shows a clear enhancement of AOD along the Longmenshan faults 7 days before the quake, which is 1 day and 4 days earlier than the reported negative and positive ionospheric disturbances, respectively, and is 1 day earlier than or quasi-synchronism with other reported atmospheric anomalies including air temperature, outgoing longwave radiation and relative humidity. Particularly, the spatial distribution of AOD enhancement is very local and it is correlated well with the active faults and surface ruptures. We suggest that this unique enhancement could be associated with the Lithosphere–Atmosphere–Ionosphere coupling process during the preparation of the Wenchuan earthquake.  相似文献   
68.
It is well known that inertial integrated navigation systems can provide accurate navigation information. In these systems, inertial sensor random error often becomes the limiting factor to get a better performance. So it is imperative to have accurate characterization of the random error. Allan variance analysis technique has a good performance in analyzing inertial sensor random error, and it is always used to characterize various types of the random error terms. This paper proposes a new method named optimization iterative algorithm based on nonnegative constraint applied to Allan variance analysis technique to estimate parameters of the random error terms. The parameter estimates by this method are nonnegative and optimal, and the estimation process does not have matrix nearly singular issues. Testing with simulation data and the experimental data of a fiber optical gyro, the parameters estimated by the presented method are compared against other excellent methods with good agreement; moreover, the objective function has the minimum value.  相似文献   
69.
简要介绍了热红外遥感技术在寻找地下热水中的应用。通过寻找山西省地下热水的实例,阐述了卫星遥感技术寻找地下热水的原理和关键技术,说明了该项技术的优势及其在寻找地下热水中的效果和应用前景。  相似文献   
70.
民用航空业的蓬勃发展对民机客户服务工作提出了新的要求,在提供优质产品的同时,如何高效保障机队正常运营成为了当前研究的重点课题。维修工程和航材支援是民机客户服务的重要组成内容,从工程实际应用出发,介绍了航材工程清单的编制流程,基于民机航线可维修性原则,着重探讨了维修性工程研究方法,并通过实例验证了航材推荐清单的有效性和实用性,可满足航材保障的要求。  相似文献   
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