Microwave Type III bursts with positive frequency drifting rate were found by Stahli and Benz (1987) for first time. Type III events are especially interesting because they are well-known to be signatures of electron beams in coronal plasma, and they are effective means for diagnosting of source plasma. A microwave burst consisting of some microwave type III burst groups was registered at Beijing Astronomical Observatory with the 2545–2645–2840 MHz synchronous observing system. The distributions of frequency drifting rate, half power duration, and intensity for each impulse in the groups have been statistically analysed. From this analysis, some important parameters for the dynamic process in the flare are deduced and discussed. 相似文献
This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H-and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust.
The time evolution behaviour of the superhumps of the dwarf nova1RXS J232953.9+ 062814 is investigated with the wavelet analysis
method. On the basis of two nights CCD photometry performed during its first superoutburst as well as other published brightness
data, we reveal the superhump's time-dependence as a function of periods and time. Our light curves, which phased in the rapid
decay ending portion of the superoutburst and in the dawn of a following normal outburst, are important to help trace the
superhump evolution for the star. Both the superhump period and the orbital period of the binary system are detected in the
present data. We obtain Psh=0.0458±0.0002d and Porb=0.0450±0.0002d. They agree with those existing values. The two periods exchanged their roles during the superhump evolution.
The general profile of brightness fading over the outbursts roughly followed an exponential decay law or a form of a five-order
polynomial.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
1 Introduction Huanghe (Yellow) River basin is located in 32°–42°N, 96°–119°E. The area of the catchment is more than 752,000km2. The river is 5464km long with a drop in elevation of 4830m. Among the whole area, the moun- tainous and stone area accounts for 29%, loess and hills area 46%, sandy area 11% and plain area 14%, respec- tively. Different natural landscapes exist in this area. The Huanghe River flows through the Loess Plateau, where the soil is eroded seriously (Wang, 2002;… 相似文献
As well known, the methods of remote sensing and Bowen Ratio for retrieving surface flux are based on energy balance closure; however, in most cases, surface energy observed in experiment is lack of closure. There are two main causes for this: one is from the errors of the observation devices and the differences of their observational scale; the other lies in the effect of horizontal advection on the surface flux measurement. Therefore, it is very important to estimate the effects of horizontal advection quantitatively. Based on the local advection theory and the surface experiment, a model has been proposed for correcting the effect of horizontal advection on surface flux measurement, in which the relationship between the fetch of the measurement and pixel size for remote sensed data was considered. By means of numerical simulations, the sensitivities of the main parameters in the model and the scaling problems of horizontal advection were analyzed. At last, by using the observational data acquired in agricultural field with relatively homogeneous surface, the model was validated.