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61.
Prediction Test for the Two Extremely Strong Solar Storms in October 2003   总被引:2,自引:0,他引:2  
In late October and early November 2003, a series of space weather hazard events erupted in solar-terrestrial space. Aiming at two intense storm (shock) events on 28 and 29 October, this paper presents a Two-Step method, which combines synoptic analysis of space weather–`observing’ and quantitative prediction – ‘palpating’, and uses it to test predictions. In the first step, ‘observing’, on the basis of observations of the source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shock waves is asymmetric and northward relative to the normal direction of their solar sources due to the large-scale configuration of the coronal magnetic fields, and the Earth is located near the direction of the fastest speed and greatest energy of the shocks. Being two fast ejection shock events, the fast explosion of extremely high temperature and strong magnetic field, and background solar wind velocity as high as 600 and 1000 km s−1, are also helpful to their rapid propagation. According to the synoptic analysis, the shock travel times can be estimated as 21 and 20 h, which are close to the observational results of 19.97 and 19.63 h, respectively. In the second step, ‘palpating’, we adopt a new membership function of the fast shock events for the ISF method. The predicted results here show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8 and 6.7%, which are consistent with the estimated results of the first step; and for the magnetic disturbance magnitude, the relative errors between the observational and the predicted results are 4.1 and 3.1%, respectively. Furthermore, the comparison among the predicted results of our Two-Step method with those of five other prevailing methods shows that the Two-Step method is advantageous in predicting such strong shock event. It can predict not only shock arrival time, but also the magnitude of magnetic disturbance. The results of the present paper tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction efficiency.  相似文献   
62.
Approach to Mountain Hazards in Tibet, China   总被引:1,自引:1,他引:0  
Tibet is located at the southwest boundary of China. It is the main body of the Qinghai-Tibet Plateau, the highest and the youngest plateau in the world. Owing to complicated geology, Neo-tectonic movements, geomorphology, climate and plateau environment, various mountain hazards, such as debris flow, flash flood, landslide, collapse, snow avalanche and snow drifts, are widely distributed along the Jinsha River (the upper reaches of the Yangtze River), the Nu River and the Lancang River in the east, and the Yarlungzangbo River, the Pumqu River and the Poiqu River in the south and southeast of Tibet. The distribution area of mountain hazards in Tibet is about 589,000 km^2, 49.3% of its total territory. In comparison to other mountain regions in China, mountain hazards in Tibet break out unexpectedly with tremendously large scale and endanger the traffic lines, cities and towns, farmland, grassland, mountain environment, and make more dangers to the neighboring countries, such as Nepal, India, Myanmar and Bhutan. To mitigate mountain hazards, some suggestions are proposed in this paper, such as strengthening scientific research, enhancing joint studies, hazards mitigation planning, hazards warning and forecasting, controlling the most disastrous hazards and forbidding unreasonable human exploring activities in mountain areas.  相似文献   
63.
1 Introduction Inrecentyearstherehasbeengrowingresearchin terestinthetwo dimensional (2 D )systemtheory .The 2 Dsystemsmayfindapplicationsinareassuchasmarineseismicdataprocessingandimageprocessing .Althoughmoreandmorevaluableresultshavebeengained ,mos…  相似文献   
64.
江山—绍兴断裂带是中国南方最重要的构造带之一。它是江南陆块与华夏陆块神功运动形成的碰撞拼贴带。它表现出明显的多期变形、构造叠加的特征:神功运动形成近东西向平卧褶皱;印支运动沿断裂带有向北西强烈的推覆挤压。断裂带不同时期的活动反映了不同特征的构造环境,形成不同的构造变形特征,并对两侧的地质历史具有明显的控制作用。  相似文献   
65.
66.
Wetlands in the Jianghan Plain are important components of wetland types in lake area in the middle and lower reaches the Changjiang (Yangtze) River and they fulfill many uses and functions related to hydrology,waste assimilation, ecosystem productivity and biodiversity. Owing to natural factors and human activities, especially excessive reclamation from lakes, the shrinking process of the lakes has been accelerated. Wetland ecosystem has shown the characteristics of vulnerability. According to the analysis of wetland ecological function in the Jianghan Plain, this paper presented an index system related to productivity, stability and environmental capacity. By using the method of Analytic Hierarchy Process, we computed the values of the relative weights of the indexes, and evaluated the vulnerability level of the wetland ecosystem by the method of multi-indexes. The case study showed that the fragile extent of wetland ecosystem in the Jianghan Plain is 5.6. This means that the wetland ecosystem in the Jiang-han Plain is laid to the state of middle vulnerability. Therefore, the wetland conservation and eco-rehabilitation in the JiangJaan Plain should be paid attention to.  相似文献   
67.
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 P sh=0.0458±0.0002d and P orb=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   
68.
It is very important to establish cooperative mechanism to guarantee all members to develop their e-conomies in the Yellow Sea Rim. In this paper, the development strategies ofshipplng centers and transportation networkare discussed based on economic giobalization tendency. The results argue that a united transportation network should bebuilt in order to promote the economic competition of Northeast Asia in the world. As a key component of the economiccooperation, a hierarchical shipping centers network should be established with Hong Kong, Shanghai, Pusan, Koho,and Tokyo as cores. The authorities of China, Japan, R. O. Korea and D. P. B. Korea should make more efforts tobuild a set of cooperation institutions based on raising the transportation efficiency.  相似文献   
69.
The exploitation and utilization of the tour resources of tournament athletics, including skiling, boat sail-ing, archery, ice engraving, snow engraving, has become a new trend of the development of Chinese tourism. Due tothe unique cold climate and superior geographic location, Harbin is a promising city for developing tour resources of tourna-ment athletics. Based on the analysis of the superiority and peculiarity of Harbin, the speculation on development of tour resources of tournament athletics in Harbin is proposed as follows : 1 ) Harbin should develop its special tour resources of tournament athletics associated with needs of market; 2) Harbin should take the advantages of rich resources and devel-op ice and snow entertainment in winter and travel for sight-seeing and spending summer;, 3) the adjustment of the layoutof ice and snow resources should be based on the idea of taking Harbin as the center and all-side opening at the largescale in the way of radiation; 4) tourism should be developed by the combined efforts of various departments to make feasi-ble plan, and the organizers should pay much attention to ensuring the safetv of tourists.  相似文献   
70.
CARBON DYNAMICS OF WETLAND IN THE SANJIANG PLAIN   总被引:2,自引:0,他引:2  
1INTRODUCTIONWetlandsplayanimportant roleintheprocessofcar-bonstorage.Thetotalcarbonstoredindifferentkindsofwetlandsisabout15%-35%ofthetotalcarboninthegloballandsoils(POSTetal.,1982;GORHAM,1991).Inaddition,wetlandsaresignificantnaturalsources fortheatmospheric CH4 (MOORE,1994).It isestimatedthatabout110×1012gCH4 originates fromanaerobicdecompositioninthenaturalwetlands,CH4 emission fromthenaturalwetlandsis15%-30%oftheglobalCH4 emission andtheCH4 emission from thepeat land at hi…  相似文献   
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