38 resultados para Florian, 1755-1794.


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农田防护林体系结构优化配置研究范志平,姜凤歧,林鹤鸣,朱教君(中国科学院沈阳应用生态研究所沈阳110015)为达到农田防护林防护效益和经济效益最大并永续利用,防护林体系必须具有在空间上布局的合理性及树种、群落和林分的多样性和稳定性特征。因此,构筑大面...

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The miscibility and crystallization behaviour of the blends of poly(ether ether ketone) (PEEK) with two thermoplastic polyimides (PI), PEI-E and YS-30, prepared by solution blending were studied by the use of small-angle X-ray scattering (SAXS), differential scanning calorimetry (d.s.c.) and polarizing microscopy techniques. The results obtained show that PEEK/YS-30 is miscible, while PEEK/PEI-E is partially miscible only in the composition range with PEI-E content up to 20 wt%. The crystallization behaviour of PEEK in PEEK/PI blends depends on the crystallization condition of the blend sample as well as the chemical structure and the content of the PI added. Our SAXS results indicate that the segregation of PI molecular chains during crystallization of PEEK chains in the blends is interfibrillar for PEEK/PEI-E blends, but interlamellar for PEEK/YS-30 blends. The compatibility and the crystallization behaviour are discussed in terms of charge transfer interaction between PI and PI molecules and between PI and PEEK molecules.

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利用22对SSR引物的扩增结果计算品种间的Jaccard相似系数,在此基础上用UPGMA方法进行了聚类分析,检测了43个春小麦品种间在DNA水平上的遗传变异。22对引物共扩增出102条多态性带,平均每对引物可扩增出4.64条多态性带,具有较好的多态性。SSR水平上43个品种间遗传距离变异范围为0.2222~0.8393,平均遗传距离GD%=0.6054。43个品种聚为两大类,除佛手麦自成一类外,其余42个品种聚为第二大类。聚类结果真实地反映了品种间基因型差异。历史上地方品种间SSR水平上的遗传变异最大,育成品种遗传多样性水平总体上呈下降趋势,且低于地方品种和引进品种。1BL/1RS易位片段特异性引物Rye检测结果显示,共有7个品种含朋1RS片段,结果需进一步证实和深入研究。

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本文介绍了我们研制的2马力水下钕铁硼电机与美国1马力电机相比所具有的特点,以及在研制中所遇到的难题及解决的方法,同时简要分析了水下钕铁硼电机在海洋机器人上的应用前景.

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As an important measure to understand oil and gas accumulation during petroleum exploration and development, Petroleum geological model is an integrated system of theories and methods, which includes sedimentology, reservoir geology, structural geology, petroleum geology and other geological theories, and is used to describe or predict the distribution of oil and gas. Progressive exploration and development for oil and gas is commonly used in terrestrial sedimentary basin in China for the oil and gas generation, accumulation and exploitation are very intricate. It is necessary to establish petroleum geological model, adaptive to different periods of progressive exploration and development practice. Meanwhile there is lack of an integrated system of theories and methods of petroleum geological model suitable for different exploration and development stages for oil and gas, because the current different models are intercrossed, which emphasize their different aspects. According to the characteristics of exploration and development for the Triassic oil and gas pool in Lunnan area, Tarim Basin, the Lunnan horst belt was selected as the major study object of this paper. On the basis of the study of petroleum geological model system, the petroleum geological models for different exploration and development stages are established, which could be applied to predict the distribution of oil and gas distribution. The main results are as follows. (1) The generation-accumulation and exploration-development of hydrocarbon are taken as an integrated system during the course of time, so petroleum exploration and development are closely combined. Under the guidance of some philosophical views that the whole world could be understood, the present writer realizes that any one kind of petroleum geological models can be used to predict and guide petroleum exploration and development practice. The writer do not recognize that any one kind of petroleum geological models can be viewed as sole model for guiding the petroleum exploration and development in the world. Based on the differences of extents and details of research work during various stage of exploration and development for oil and gas, the system of classification for petroleum geological models is established, which can be regarded as theoretical basis for progressive petroleum exploration and development. (2) A petroleum geological model was established based on detailed researches on the Triassic stratigraphy, structure, sedimentology and reservoir rocks in the Lunnan area, northern Tarim Basin. Some sub-belt of hydrocarbon accumulation in the Lunnan area are divided and the predominate controlling factors for oil and gas distribution in the Lunnan area are given out. (3) Geological models for Lunnan and Jiefangqudong oil fields were rebuilt by the combinations of seismology and geology, exploration and development, dynamic and static behavior, thus finding out the distribution of potential zones for oil and gas accumulations. Meanwhile Oil and gas accumulations were considered as the important unit in progressive exploration and development, and the classification was made for Lunnan Triassic pools. Petroleum geological model was created through 3D seismic fine interpretation and detailed description of characteristics of reservoir rocks and the distribution of oil and gas, especially for LN3 and LN26 well zones. The possible distribution of Triassic oil traps and their efficiency in the Lunnan area has been forecasted, and quantitative analysis for original oil(water) saturation in oil pools was performed. (4) The concept of oil cell is proposed by the writer for the first time. It represents the relatively oil-rich zones in oil pool, which were formed by the differences of fluid flows during the middle stage of reservoir development. The classification of oil cells is also given out in this paper. After the studies of physical and numerical modeling, the dominant controlling factors for the formation of various oil cells are analyzed. Oil cells are considered as the most important hydrocarbon potential zones after first recovery, which are main object of progressive development adjustment and improvement oil recovery. An example as main target of analysis was made for various oil cells of Triassic reservoir in the LN2 well area. (5) It is important and necessary that the classification of flow unit and the establishment of geological model of flow unit based on analysis of forecast for inter-well reservoir parameters connected with the statistical analysis of reservoir character of horizontal wells. With the help of self-adaptive interpolation and stochastic simulation, the geological model of flow units was built on the basis of division and correlation of flow units, with which the residual oil distribution in TIII reservoir in the LN2 well area after water flooding can be established.

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利用花江岩溶峡谷区南坡不同石漠化程度的5个独立的岩溶峰丛洼地系统景观要素的实测数据,分析了多样性、优势度、破碎度、分离度等景观格局指标的变化规律及其所指示的生态学意义。结果表明,这些指标在不同峰丛洼地系统都能较好地评价石漠化过程中景观格局的动态变化规律,对分析石漠化土地的发展趋势具有较好的指示意义。但多样性指数、优势度指数、均匀度指数也与各峰丛洼地系统的景观基质有关,在不同石漠化程度的峰丛洼地系统中,反映的景观生态意义是不一样的。景观格局分析不仅强调面积,而且还考虑所研究石漠化土地的空间分布特征(格局)、景观组成特点与石漠化过程的关系和对石漠化的影响,在石漠化程度判定和石漠化指标的研究中景观格局是一个不可忽视的问题。