排序方式： 共有66条查询结果，搜索用时 11 毫秒
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地图图书产品精品化战略的实施 总被引：1，自引：0，他引：1
论述了地图图书精品化的必要性以及精品地图、图书的策划和出版 ,提出了地图精品化战略的实施办法。 相似文献
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江苏省农村城镇化的村庄规模变动研究 总被引：5，自引：0，他引：5
该文分析江苏省农村城镇化过程中的村庄规模变动，指出当前主要问题是：村庄人口减少和用地面积增大；农宅占地过大；小城镇吸纳力不足。探讨其变化的动力机制，城镇空间扩展和基础设施建设是主要的外因，内部建设用地变动是主要的内因，提出未来村庄建设要加强村庄规模的调控力度，适应农村城镇化的需要。 相似文献
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We documented the pattern of cell development in Euplotes charon. The ontogenesis of this species was similar to many of its congeners, except for the formation of the caudal cirri. In E. Charon, a caudal cirrus is formed posterior to each of the rightmost two or three dorsal kinety anlage in the proter, and the second
rightmost dorsal kinety in the opisthe. In addition, two caudal cirri are formed posterior to the rightmost dorsal kinety
in the opisthe. This pattern of development represents a completely new type. Based on our evaluation, and in comparison with
previous studies, we also conclude that the pattern of cell development is variable among species in the Euplotes genera. The variation is particularly evident during the formation of frontoventral and caudal cirri. Based on the segmentation
pattern of frontal-midventral transverse cirral anlagen, cirri reduction, and migration of frontoventral cirri, we identified
five types: the affinis-type, the eurystomus-type, the charon-type, the raikovi-type and orientalis-type. Euplotes (s. l.) can also be divided into three types based on the formation of caudal cirri: focardii-type, vannus-type and charon-type. Indeed, we conclude that the number (one or two) of marginal cirri should be given as much consideration as the genetic
separation. Given this, we reassessed the validity of using genetic separation to classify the group. Generally, the morphogenetic
data disagreed with the molecular data (SSrRNA gene sequences). Given these discrepancies, it is too early to draw conclusions
on the systematic arrangement of this species-rich taxon. 相似文献
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