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991.
本文从萤石资源的分布特点、开发利用状况、国内外市场需求及资源保证程度等不同角度进行综合全面分析预测,阐述了丽水地区发展氟化学工业的可行性。  相似文献   
992.
本文在电子回旋脉塞不稳定性理论的基础上,着重讨论了等离子体背景参数ω_(pe)/Ω_e对尖峰辐射性质的影响,内容包括:该参数的物理意义、取值范围,以及在尖峰辐射性质中,对ω_(pe)/Ω_e的变化比较敏感的偏振和谐波结构,等等。  相似文献   
993.
We used the tropical oceanic planktonic diatom species Nitzschia marina, Rhizosolenia bergonii and Azpeitia africana/Azpeitia neocrenulata, most commonly found in the surface sediments of the northeasternmost South China Sea (SCS) where the Kuroshio Current enters the SCS through the Bashi Strait north of Luzon, to analyse the influence of the the Kuroshio Current on the SCS. The impact of the Kuroshio Current seems to be relatively strong during major warm periods and, to a lesser degree, in minor warm periods during the last 115 000 years. The strongest influence took place during the main part of the Holocene and during the very late phase of Marine Isotope Stage (MIS) 5e. It is possible to distinguish two magnitudes of change in the impact of the Kuroshio Current on the SCS: large changes occurred at shifts between glacial and interglacial conditions, while smaller changes seem to have recurred in both glacial and interglacial episodes as well as during the Holocene. Climatic/oceanographic changes and sea‐level variations were possibly the two most important mechanisms for the varying influences of the Kuroshio Current on the SCS. The interaction between the Kuroshio Current and monsoon‐related processes may also have played a role. However, because of restricted knowledge of the present‐day Kuroshio Current and the absence of a modern analogue to the ancient SCS due to the marked changes in palaeogeography, this relationship is difficult to establish. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
994.
全面叙述中国地壳运动观测网络中25个基准站之一——福建GPS基准站的设计、选址、建造和仪器安装等建设过程及试运行至今的情况和有关参数。其中对某些防护措施如防雷措施有较详细说明。为今后GPS基准站的建设提供了系统性的经验。  相似文献   
995.
本文在测量的基础上,对热量平衡各分量在大棚内、外的差异,进行了比较与分析,对大棚生产管理有重要参考价值。  相似文献   
996.
Remote sensing technique has played an important role in land use dynamic monitoring, but as for the land use dynamic monitoring at county level, traditional remote sensing methods such as satellite imagery visual interpretation and computer classification can not meet its demand for accuracy. The result of 1: 10 000 land use investigation map has high accuracy, but this method can not be used to dynamically monitor the land use because of its big expenses, long period and difficulty in updating data. In this paper, the characteristics of physiognomy, climate and the status of land use in Dehui County are taken into consideration and a set of method, which takes use of 3S techniques and applies to Northeast China Plain, is come up with. When the land use type of a land parcel changed as a whole, the date updating can be make by changing its land type ID in the attribute table in a GIS. When the land use type of an irregular area changed, GPS receivers are used to position its border. This set of method is characteristic of high accuracy and low expenses. It gets the information of land use change timely and can be used to dynamically monitor the land use. Foundation item: Under the auspices of the key project of the National Ninth Five-year Plan (96-B02-01-07). Biography: LI Lin-yi (1968 —), female, a native of Jilin, Ph. D. candidate of Changchun Institute of Geography, the Chinese Academy of Sciences. Her research interest includes land use change monitoring and crop yield estimation using “3S” techniques.  相似文献   
997.
A type of pulsation in a time scale of seconds superimposed on microwave burst at 9.375 GHz has been found during the twenty-second solar active maximum period by us. This phenomenon is quite different from radio spike emission at decimeter and long centimeter wavelengths. The flux level of the bursts rises as the repetition rate of pulsations increases, following an approximate linear relationship. This feature resembles that at mm wavelength, but some other features are different. Some mechanisms for interpretation have been proposed.  相似文献   
998.
本文探讨了几种推算山区≥10℃积温的方法,认为由我国学者所采用的直方图推算法以及计量地理学中的三元线性回归数学模型推算法,在实际应用中都存在不完善和局限性,将两者结合起来进行复合推算,是一种较理想的研究方法。  相似文献   
999.
1 INTRODUCTIONSolar microwave bursts are usually produced by dtherellt radiation mechanisxns: gyroresonance absorption, Coulomb brernsstrahlung of the thermal baCkground plasma, as well asgyrosynchrotron radiation of the nonihermal electrons (Hildebrandt et al. 1998). Meanwhile,cyclotron or synchrotron maser instabilities may be responsible for microwave spaaes, blips, andtype ill bursts (Wu 1985; Huang 1987; Huang et al. 1996; Huang 1998), which are usuajly superposed on the ambient mi…  相似文献   
1000.
A linear regression analysis of 28 selected tide-gauge stations of the Zhujiang Estuary shows that there has been a tendency of local sea level rise at a rate of 2.028 mm per year. The origin of the variation is significantly attributed to the local tectonic movement of discrepant fault-block. Based on this, four types of relative local sea level changes are classified. According to calculation, half of the fertile land, or 800 km2 of the delta plain will have been submerged by sea water by about 2040. This will yield a significant influence on the economic construction and human activities.  相似文献   
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