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61.
Great advances in statistical meteorology have been made in recent years in China.The mainpoints are as follows:Introducing entropy principle into meteorology,entropy meteorology isfounded;Introducing memory function,self-memorization equation of atmospheric motion isderived;The fuzzy reasoning is introduced into meteorology;Using the method of nonlineardynamics in researches of climatology,some forecasting schemes of phase space are proposed;Chebyshev polynomial is generalized at irregular grids and an iterative scheme for forecast of timeseries is proposed:The wavelet transform is used in researches in climatology;Logisticdiscrimination is used in meteorology and quadratic discrimination and stepwise discrimination areinvestigated;The theory on grey system and the multilevel recursion proposed by Chinesescientists are introduced into meteorological forecast.In addition,complex empirical orthogonalfunction,singular value decomposition,projection pursuit,principal oscillation patterns and so onare also introduced.All the above methods have played great roles in operational weatherforecasts. 相似文献
62.
瑞利波探测在石炭井三矿的应用 总被引:2,自引:2,他引:0
针对石炭井三矿的具体地质、地球物理条件介绍了矿井瑞利波系统在井下的施工、数据采集、资料处理、解释推断等诸方面的方法技术。举例指出该探测系统在剩余煤层厚度探测、掘进巷道超前探测地质构造、石门揭煤判断煤层位置几个方面的地质效果。 相似文献
63.
迄今,用于煤矿井下独头巷道超前勘探的有效手段寥寥无几。常规的钻探方法费工、费时、效率很低,而且有引起突水的危险。瑞雷波勘探方法是一种使用瑞雷面波作为有效波进行零到几十米范围内地震勘探的新型物探方法。它的测线基距与勘探深度的比值可以达到1∶20以上,即1~2m的测线布置,勘探深度可达30~40m以上。完全适用于独头巷道超前勘探的需要。把这样一种地面地质勘探的方法技术移植到井下,在煤巷、岩巷中进行超前探测断层、空巷、冲刷带的试验并获得成功,无疑为煤矿井下独头巷道的超前探测开创了一种全新的物探手段,必将在煤矿的安全掘进和生产方面发挥重要作用。 相似文献
64.
Peter M. Allen Jeffrey G. Arnold Lance Auguste Joseph White John Dunbar 《地球表面变化过程与地形》2018,43(1):202-217
Gully erosion begins in streambanks and uplands as a consequence of adjustments in driving forces on the landscape imposed by changes in land use or climate. The deleterious effects of gullies worldwide have led to many site‐specific studies of gully form and function. In the continental United States, gully erosion in agricultural land has destroyed valuable farmland yet, prediction of gully processes remains problematic on a national scale. This research has proposed a simple method to predict gully headcut advance. When combined with SWAT hydrologic flow routines, the model predicted gully headcut advance with reasonable accuracy on a daily time step for time periods exceeding two decades. The model was tested in two distinct land resource areas of the United States with differing climate, soils, cover and drainage. The inputs for the headcut model have been kept simple as the model will be applied over large areas. Model inputs consist of headcut height, headcut resistance (based on soil erodibility and a root‐cover factor), and daily flow. The model is compared with an annual time step model used in assessment of headcut advance and appears to offer a better way to assess gully headcut advance. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
65.
ZHANG Wei YAN Minhua CHEN Panqin XU Helan 《中国地理科学(英文版)》2008,18(1):93-100
Regional climate models have become the powerful tools for simulating regional climate and its change process and have been widely used in China. Using regional climate models, some research results have been obtained on the following aspects: 1) the numerical simulation of East Asian monsoon climate, including exceptional monsoon precipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summer rain belt and so on; 2) the simulation of arid climate of the western China, including thermal effect of the Qinghal-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects (CO2 doubling) upon climate in the western China; and 3) the simulation of the climate effect of underlying surface changes, including the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil degradation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea contrast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effect of vegetation changes on the regional climate, etc. In the process of application of regional climate models, the preferences of the models are improved so that better simulation results are gotten. At last, some suggestions are made about the application of regional climate models in regional climate research in the future. 相似文献
66.
海洋植物组织和细胞培养研究进展 总被引:3,自引:0,他引:3
对海藻组织和细胞培养研究进行了综述。认为我国在该领域的研究起步晚、人员少,但在经济海藻应用研究如紫菜体细胞育苗上具有国际领先水平。为促进海藻组织和细胞培养技术的产业化,应加强藻类组织培养工作者与高等植物组织培养工作者之间的交流和合作,以组织培养技术中较为成熟的离体快繁为突破口,进行市场急需商品苗的快速生产。利用海藻组织和细胞培养进行次生物质合成和特殊药物转化的研究亦具有潜在的应用价值。 相似文献
67.
南海现代海平面变化研究的进展 总被引:7,自引:0,他引:7
本文根据笔者近年对广东海平面变化的研究,并参考前人的研究结果,对南海现代海平面研究的进展进行了较系统的评述.认为数十年来南海相对海平面总体上呈上升趋势,上升速率一般小于2.5mm/a.1.8mm/a或1.9mm/a可以近似地作为绝对海平面上升速率.预测2030年或2025年相对海平面上升幅度为20~25cm. 相似文献
68.
Andrea?Tallarico Stefano?SantiniEmail author Michele?Dragoni 《Pure and Applied Geophysics》2005,162(12):2273-2298
The Central Apennines, Italy, are characterized by moderate seismic activity on normal faults, oriented in directions parallel
to the Apenninic chain. The subject of this study is the Umbria-Marche Apennines, a segment approximately 200-km long, where
three main seismic events occurred in the last three decades. The 1979 Norcia earthquake was a Mw = 5.8 event, taking place at the south end of the considered segment. The 1984 Gubbio earthquake was a Mw = 5.6 event which took place at the north end. The 1997-1998 Colfiorito sequence constituted 8 main shocks with magnitudes
Mw between 5 and 6 and epicenters located between the Gubbio and the Norcia earthquake areas. A model made of an elastic half-space
is considered, in which the seismic sources are represented by rectangular dislocations which have the appropriate values
of source parameters, and in which the static stress field produced by each event is calculated. The analysis of the Coulomb
stress change (ΔC) as a function of time shows that the coseismic stress transfer and fault interaction played an important role in the region
during the past three decades: 7 earthquakes of the 9 considered took place where ΔC>0. Such an interaction has been confirmed by the analysis of the aftershocks in the Colfiorito zone post September 26, 1997:
about the 61% of the aftershocks considered took place where ΔC>0. The comparison between the ΔCs due to the coseismic stress transfer and the rate ΔĊt due to the tectonic stress allows us to quantify the time advance of the earthquakes. The ΔCs pattern shows positive values in two areas that can be regarded as historical seismic gaps. 相似文献
69.
70.
我国地震监测预报研究的主要科学进展 总被引:22,自引:4,他引:18
回顾和总结了1966年邢台地震以来我国地震监测预报研究的主要科学进展,并将其归纳为建立了4个方面的基础,即: 地震预测预报的多学科观测基础;获取了一批中强以上乃至大地震资料的震例基础;建立了经验性预测方法和判据的经验预报基础;初步探索了地震孕育发生的地震预报理论基础。文中还阐述了我国20世纪90年代在长期预报、中期预报、短临预报的预报效能。 相似文献