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961.
报道了光激荧光粉的合成工艺及由它制成的X射线图像板的性能。该图像板在X射线曝光后,并经装在激光数字转换器上的He-Ne激光扫描,就能得到临床上所需要的图像。 相似文献
962.
牛忠荣 《合肥工业大学学报(自然科学版)》1992,(4)
本文研究单向变厚度Levy型板的弯曲问题,用单三角级数把矩形板的控制方程化成常微分方程边值问题,然后采用两点边值问题的插值矩阵法求解板的方程。通过示例,显示本文求解变厚度板的方法精度高,使用方便。 相似文献
963.
杨继续 《河南科技大学学报(自然科学版)》1992,(1)
本文提出一种可以精确考虑平板的横向剪切变形和法向正应力影响的平板理论。在这种新的理论中,横向剪应力的分布用含有若干个待定函数的多项式表示,这些特定函数可以用三维弹性力学基本方程和简单的线性代数运算来确定,不需解附加的微分方程,而多项式的项数则由横向载荷的分布来决定。根据这种新理论所取得的方程及其解答能够比现有理论更精确的反映不同的载荷分布对于应力分布及位移的影响。本文用例题说明了这种新理论的计算方法。 相似文献
964.
965.
The relatively abundant palynomorphs were recovered from the samples of the first paleosol layer of core CY in Shanghai for the first time. A total of 55 genera and families of spore, pollen and phytoplankton were identified. According to the characteristics of the palynological assemblages, the depositional conditions in the development period of the paleosols were discussed and the microfossil evidence to study the origin of the paleosols in the Yangtze Delta area was provided as well. The research results show that paleosols should be freshwater deposits. The palynological assemblage sequence in the first paleosol layer reveals fluctuations of freshwater palynomorphs, mainly Concentricystis, and terricolous herbs pollen, reflecting the alternations of deposition and exposure in the development period of the paleosols. Concentricystis developed prosperously in the period of flood, while terricolous herbs grew on the emerged land in the period of exposure. The variations in the palynological assemblages suggest that the depositional conditions were various during the formation of the paleosols, and resulted in obvious stage characteristics of the paleosol's development. The dinoflagellate cysts occur in low abundance in the palynological assemblages of the first paleosol layer of core CY, indicating that the area where core CY lies was influenced by seawater in the depositional period of the parent materials of the paleosols. 相似文献
966.
In the areas of China access into WTO Agreements, Chinese government has made lots of promises in reducing tariffs of some industrial products. While industrial products make up a very large share of import and export, so nearly all kinds of them will be influenced, especially those which are protected by means of national tariffs and taxes and non- tariffs barriers on import-sand, to a lesser extent, on exports. Meanwhile we have noticed that most of these industries are the pillar ones of Yangtze Delta. As it is well known that Yangtze Delta has become the most developed area in Yangtze valley or even in China and had an important effect on China economy. Thus entry to the WTO requires reform to be accelerated in this district so as to put the industry of this region in a position to be able to cope with the greater foreign competition that will follow accession to the trade body. 相似文献
967.
968.
Masataka Watanabe 《科学通报(英文版)》2005,50(7):679-684
Land and sea are linked closely by large rivers throughrunoff and sediment discharging and biochemical materialtransferring into the sea[1?3]. The processes carried out byenergy exchange have been in a sensitive response toglobal change[4]. To study the mechanism of sediment transport in the river basin as to reflecting hydromor- phological and climatological controls is thus becoming vital for earth scientists, at present and in the near future since any change in fluvial landform is of a gre… 相似文献
969.
970.
针对K近邻方法分类准确率较高的特性,提出了一种基于相似度判据的K近邻分类器车牌字符识别方法.通过大量实验,选取字符的网格特征和轮廓特征作为分类依据,用特征融合方法将两种特征合并,实现特征的串行融合.根据相似度判据作K近邻分类,实现了一个车牌字符识别系统.实验表明,这种方法具有良好的识别效果,鲁棒性强,具有较大的实用价值. 相似文献