The exponential growth of storage space in blockchain network has become a serious problem to hinder the distribution of blockchain and the expansion of blockchain nodes. In this paper. We propose a security strategy for distributed storage blockchains, which can delete part of blockchains so that nodes only store part of a blockchain. We design a kind of semi-full node between full node and light node according to the requirement of the strategy, besides describe the process of deleting block and synchronizing block, and the running logic of the semi-full node. Finally, we perform comprehensive experiments of the truncated MCMC random algorithm. The results show that in the case of multi-node, the truncated block will not affect the block chain network. Compared with the traditional block design, our storage strategies can reduce storage requirements under most of situation, thus enable blockchains to be deployed on mobile or smaller storage computers.

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A large-scale urban construction was carried out in Qingdao during German Occupation Period (1897-1914) as the first upsurge in Qingdao's urban development. Influenced by western architectural culture, buildings, as cultural carriers, embody the culture and arts of the specific historical period and reflect the architectural and cultural trends appeared in urban development and social evolution.

The study on the resistance of different wetland plants to wastewater duress is the key to ecological wastewater treatment technology. This paper studies the change of soluble protein content in 4 common wetland plants (Phragmites communis, Typha angustata, Arundo donax and Canna generalis) in Shandong in different wastewater duress time. The results show: when the wastewater duress time is 2 days and 4 days, soluble protein content in Phragmites communis has minimal change, and its anti-stress capability is the strongest; when the wastewater duress time is 6 days, soluble protein content in Canna generalis has minimal change, and its anti-stress capability is the strongest, followed by Typha angustata.