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811.
����������ʽ���Ƶ� 总被引:4,自引:0,他引:4
邓永和 《大地测量与地球动力学》2009,29(3):128-130
?????????????????????????????????????????????????????????????????????÷????????????????????????????????? 相似文献
812.
InSAR��ϻ��߹��Ʒ����о� 总被引:3,自引:1,他引:2
??????????????λ???α??????????????????????????????InSAR???????е????????????3?????????????????????????飬?о??????????????????????????????????????о????б???????????????????????????????????????????????????????????????????????????????????????????????????? 相似文献
813.
邓永和 《大地测量与地球动力学》2009,29(1)
利用误差传播律和点在任意方向的位差理论,提出并论证了交通线路上任一点对应中桩的横向位差为零,纵向位差等于该点的点位误差。对中桩的误差曲线和误差椭圆的分析认为,误差椭圆无实际意义,误差曲线实用而有效。 相似文献
814.
???????????????????и????λ????????????????GPS??λ????????????????????λ???????????????????????????ɡ???????????????????λ?????????????????????????????????????????? 相似文献
815.
���̨��б��ϫ�α�۲�����������ӳ��Ч������ 总被引:1,自引:1,他引:0
??????????????????б??1994??2008?????б????????????????????????????14?????б????????????????????????????????????5???????????????????????????е??????????????????????б?????????????????????????????3???????????????????????????????????????????????????5.7??????8.0???????????????? 相似文献
816.
基于ARM和SD卡的微动数据采集系统数据存储技术研究 总被引:1,自引:0,他引:1
为满足微动数据采集系统的大数据量、低功耗要求,用SD卡存储微动数据采集系统采集得到的数据。阐述如何实现SD卡在以三星ARM9-s3c2410为硬件平台、Linux操作系统为软件平台的微动数据采集系统中的存储功能。 相似文献
817.
����ǿ��ǰ���ϵ��������TEC�쳣�����о� 总被引:2,自引:0,他引:2
???????GPS??TEC???????VTEC???????????15?????????????????ο????????????????????VTEC???? 2006??12??26??????????????7.2???????2008??5??12????8????????????????????????????8???????????????????????????????????????????????????????????????????VTEC????????????????????????????????VTEC?????????????????????????????????????????????????????? 相似文献
818.
In order to reveal transpiration rates of wetland plants and its relationships to micro- meterological factors in a mountain valley wetland, relative humidity, air temperature, leaf temperature, soil temperature, photo flux density and transpiration rates were measured once two hours in a Carex meyeriana wetland of the Changbai Mountain valley in dry (July) and wet (September) of 2003, respectively. Results showed that the tendency of "decreasing after increasing" was obvious in wet season. However, a relatively stable trend was observed for the transpiration in dry season.. Generally, the photon flux density of Carex meyeriana was higher in wet season than that in dry season. However, the variabilities of leaf temperature, air temperature and relative humidity were similar in both seasons. Higher transpiration rates of Carex meyeriana leaves were observed in July (varied from 40 to 150 mol.m^-2.s^-1) compared to those (varied from 7 to 14 mol.m^-2.s^-1) in September. Transpiration rates were significantly correlated with air temperature (P〈0.01), leaf temperature (P〈0.01), and wind speed (P〈0.05), but correlationship between relative humidity and photo flux density was not significant (P〈0.05). 相似文献
819.
820.
Zifa Deng Shuqing An Congjiao Zhao Lin Chen Changfang Zhou Yingbiao Zhi Hongli Li 《Estuarine, Coastal and Shelf Science》2008,76(4):818-826
Spartina alterniflora Loisel., an extensively invasive species on the Chinese coast, is a focus of increasing management concern due to its high expansion rate in estuaries and tidal zone, and the significant damage it causes to native ecosystems. In order to understand the processes and mechanisms of invasion of S. alterniflora in China, the impact of three sediment types (sand, sand–loam mixture and loam) and five buried patterns (unburied, 50% burial of initial plant height, 75% burial of initial plant height, complete burial and repeated burial) on the growth of seedlings or ramets was investigated. Results showed that each of the three factors (sediment types, burial pattern and plant materials) and interactions between/among them, significantly affected height and clonal growth, and biomass accumulation and allocation. Plant height, total biomass and number of new vegetative propagules significantly increased with progressive burial treatments. However, the complete burial treatment resulted in the death of all plant materials, and the maximum values of three parameters were found in the 50% burial or repeated burial treatments. Plant responses were determined by the instantaneous thickness of sediment of each time burial rather than by the total quantity of repeated burial. The growth of S. alterniflora was not shown to be dependent on specific types of sediment in sedimentation environment. In contrast to the unburied control, the proportion of primary tillers produced directly from initial individuals and the ratio between the aboveground and belowground biomass were greater under burial treatments. Seedlings produced more new vegetative propagules than vegetative offspring in all experimental treatments, and the former were apt to produce ramets from rhizomes rather than primary tillers. It is concluded that under various sedimentation environments, the clonal spread efficiency of seedlings was higher than that of vegetative offspring, and there is a positive feedback relationship between sedimentation and the growth of S. alterniflora. Thus, moderate sedimentation may stimulate the invasion of exotic species, S. alterniflora in coastal China. 相似文献