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901.
Wang Shujuan Yan Yihua Zhao Ruizhen Fu Qijun Tan Chengming Xu Long Wang Shijin Lin Huaan 《Solar physics》2001,204(1-2):153-164
25 MHz–7.6 GHz global and detailed (fine structure – FS) radio spectra are presented, which were observed in the NOAA 9077
active region for the Bastille Day (14 July 2000) flare at 10:10–11:00 UT. Besides broadband radio bursts, high-resolution
dynamic spectra reveal metric type II burst, decimetric type IV burst and various decimetric and microwave FSs, such as type III
bursts, type U bursts, reverse-slope (RS)-drifting burst, fiber bursts, patch and drifting pulsation structure (DPS). The
peak-flux-density spectrum of the radio bursts over the range 1.0–7.6 GHz globally appears as a U-shaped signature. Analyzing
the features of backbone and herringbones of the type II burst, the speeds of shock and relevant energetic electron beams
were estimated to be 1100 km s−1 and 58 500 km s−1, respectively. Also the time sequence of the radio emission is analyzed by comparing with the hard X-rays (HXRs) and the
soft X-rays (SXRs) in this flare. After the maxima of the X-rays, the radio emission in the range 1.0–7.6 GHz reached maxima
first at the higher frequency, then drifted to the lower frequency. This comparison suggested that the flare included three
successive processes: firstly the X-rays rose and reached maxima at 10:10–10:23 UT, accompanied by fine structures only in
the range 2.6–7.6 GHz; secondly the microwave radio emission reached maxima accompanied by many fine structures over the range
1.0–7.6 GHz at 10:23–10:34 UT; then a decimetric type IV burst and its associated FSs (fibers) in the range 1.0–2.0 GHz appeared
after 10:40 UT. 相似文献
902.
高密度电阻率法比常用的电阻率法有更多的优点,一次可以完成纵、横二维勘探过程,所以观测精度高,采集数据可靠,获得地质信息丰富。本文主要从高密度电法的工作方法、成果解释来说明用高密度电法探测西安地区地裂缝的可行性。 相似文献
903.
强作用对奇异星观测效应的影响 总被引:1,自引:0,他引:1
奇异星是类似于中子星的曲奇异夸克物质组成的致密天体。本文研究了夸克这间的强作用对奇异星观测效应的影响。我们认为:(1)中子星转变为奇异星的行为是一种大的周期突变(glitch)现象,这种现象取决于夸克间的强作用;(2)强作用使高温奇异星的振动阻尼也有效,这可能是驱动超新星爆发的新机制;(3)强作用加强了高温情形下奇异星和中子星在转动上的差别,奇异星的最小周期比中子星的小。 相似文献
904.
Wu Chaoyuan Li Jiajun Xia Enzhan Peng Zhuosheng Tan Shuzhi Li Jun Wen Zongcun Huang Xiaohang Cai Zulin Chen Guojun 《中国海洋湖沼学报》1989,7(4):327-334
A 2-year study onKappaphycus alvarezii (Doty) Doty introduced to Hainan Island from the Philippines in 1985 showed promising results. The average daily growth in
weight reached 10% at a favourable temperature of about 26°C. Experimental results showed that timely cutting of the plant
was an effective way to obtain new cuttings for cultivation and accelerate growth. New cuttings 0.05 kg in weight are suggested
to be used as “seeds” and the old plant should be harvested. At present, artificial cultivation with a type of underwater
raft applicable in places where there is strong wind will expand cultivation to more regions in Hainan Province.
This paper was originally published in Chinese inOceanologia et Limnologia Sinica
19(5): 410–418, 1988. The plant under discussion wasEucheuma alvarezii Doty which was previously calledE. striatum in the article, and which now becomesKappaphycus alvarezii (Doty) Doty. To the original title, “in China” was added. Only the essence of the original article was presented. 相似文献
905.
A simulation of accretion of a string loop has been done. It shows that aspherical accretion is essential for large-scale loops. All configurations found in the distribution of galaxies, such as filaments, pancakes, bubbles, and voids, can be formed by the accretion of cosmic strings. 相似文献
906.
Fang Zongyi 《Acta Meteorologica Sinica》1988,2(4):546-548
At 0430 Beijing summer Time 7 September 1988,the first Chinese meteorological satellite.named Fengyun-1(FY-1 meaning observing the wind and clouds in the atmosphere) was launched into the near-polar sun-synchronous orbit successfully at the Taiyuan Satellite Launching Center,Shanxi Province by Long March-4 launching vehicle which was developed by the Ministry of Aeronautics and Astronautics.FY-1 satellite is a hexahedron of 1.4m×1.4m×1.2m (Fig.1).The attitude of satellite is three-axis. stabilized.The satellite at an altitude of 900 km operates around the earth 14 passes per day with a period of 102.86 min.The main instruments aboard the satellite are two Advanced Very High Resolution Radsometer (AVHRR) and Space Environmental Monitor.Table 1 gives the major specifications of AVHRR. 相似文献
907.
Nicheng?ShiEmail author Zhesheng?Ma Ming?Xiong Mingquan?Dai Wenji?Bai Qingsong?Fang Binggang?Yan Jingsui?Yang 《中国科学D辑(英文版)》2005,48(3):338-345
(Fe4Cr4Ni)9C4 is a metal carbide mineral formed by combination of Fe, Cr and Ni with C. It occurs in a chromite deposit in
the Luobusha ophiolite, Tibet. Based on the determination of its crystal structure, the empirical formula is (Fe4.12Cr3.84Ni0.96)8.92C3.70
and the simplified formula is (Fe4Cr4Ni)4C9. The mineral is hexagonal with a = 1.38392(2) nm, c = 0.44690(9) nm, pace group P63 m c, Z=6 and the calculated specific gravity Dx = 7.089 g/cm3. Fe, Cr and Ni occupy different crystallographic sites and their coordination numbers are approximately 12,
forming an alternate stacking sequence of flat and puckered layers along the c axis. Some metallic atoms have a defect structure. The interatomic distances of Fe, Cr and Ni are 0.2525-0.2666 nm, and the
distances between Fe, Cr, Ni and C are 0.1893-0.2169 nm. The coordination number of carbon is 6. It occurs in interstices
of the metallic atoms Fe, Cr and Ni to form trigonalprismatically coordinated polyhedra. These coordination polyhedra are
linked with each other via shared corners or shared edges into a new type of metal carbide structure. 相似文献
908.
Using spectrographic plates obtained on 11 nights during its 1979/1980 eclipse, we have obtained a radial velocity curve of ζ Aur. Our results are in general agreements with previous measurements, but we note that the radial velocity just before the total eclipse showed an appreaciable decrease. A preliminary discussion is made. 相似文献
909.
The problem of automatic detection of seismic waves by large telemetered seismic networks such as the Mexican Continental Aperture Seismic Network (RESMAC), is extended here to include determination of seismic first-arrival and S-phase-arrival times. A short general outline of the detection problem background and a small introduction to the autoregressive model (AR) concept are presented. Several automatic detection algorithms were implemented and compared with a newly developed autoregressive algorithm. Careful consideration of the advantages and disadvantages of each method determined that a mixed detection scheme is optimal and suitable for RESMAC. A few examples are shown that illustrate the relative performances of the methods tried here. The proposed detection scheme has the following characteristics: (a) First-arrival detection, based on a simple (average of squared input) characteristic function, and a trigger criterion that uses as a distortion measure the long-average-to-short-average ratio of the characteristic function, checked using a duration criterion; (b) use of two threshold values, one for triggering, and another for beginning the backward search for the phase arrival time; (c) use of the autoregressive model (AR) method, with the Itakura-Saito distortion measure, for S-phase detection, checked using both duration and amplitude criteria; and (d) characterization of the reliability of the determinations for their subsequent use in automatic location programs, alarms, etc. The automatic detection scheme has proved effective. 相似文献
910.
本文从讨论能源的概念和分类入手,阐述了我国能源资源的储量及其地理分布,并针对能源开发利用中的特点和问题,提出了合理利用我国能源资源的若干建议。 相似文献