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Pinus tabulaeformis is an endemic species in northern China. The northern edge of its distribution corresponds to the northern margin of the monsoon climate. Several stands of Pinus tabulaeformis beyond its major range of distribution were found on the southeastern edge of the Inner Mongolia Plateau. Phytosociological analysis shows that the community(More)
On the basis of field investigations, the timberline range of Beitai, the Xiaowutai Mountains was carved up, and the changes in the makeup and diversity of plants with the altitude were discussed. The results showed that the timberline with gradual changes in the northern slope of Beitai ranged from 2620-2800 m. In timberline, herbaceous plants were rich,(More)
p c t p s ( o a a 1 o t ( 1 u a h H p i w Oxygen and hydrogen isotopic compositions of meteoric water re known to correlate with surface air temperature, except in ropical areas. This relationship has been described using a numer of terms corresponding to specific observations, such as latiude, altitude and seasonal effects. However, these temperature(More)
This paper studies a novel scheme of watermarking relational databases for copyright protection based genetic algorithms. In this algorithm, GA is used in watermark signal processes, and associated novel watermark insertion algorithm and detection algorithm are proposed. Thus, the watermark signal in this method is expected to be more meaningful and has(More)
By introducing public key cryptography, a novel algorithm for watermarking relational databases is proposed. In this algorithm, asymmetric keys are used in insetting and detecting database watermark processes, and users canpsilat get anything of the private key copyright watermark information or destroy database watermark through public key. Watermark(More)
Topographic conditions play an important role in controlling land cover dynamic processes. In this study, remotely sensed data and the geographic information system were applied to analyze the changes in land cover along topographic gradients from 1978 to 2001 in Beijing, a rapidly urbanized mega city in China. The study was based on five periods of land(More)
Biodiversity patterns of the woodland-steppe ecotone in southeastern Inner Mongolia were investigated. Controlled by climatic factors, the plant species diversity of the woodland-steppe ecotone is moderate as compared with the adjacent woodland and steppe communities. From woodland through woodland-grassland and woodland-steppe to steppe, about 2/3 species(More)
Originated from various vegetation types, psammophytic woodlands on sandy dunes of the steppe zone in Inner Mongolia are rather diverse. The commonest types are woodlands with Pinus sylvestris var. mongolica, P. tabulaeformis, Picea meyeri, Juniperus rigida, Populus davidiana, and Betula platyphylla. In Daqinggou of Horqin sandy land, a mixed broad-leaved(More)
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