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Under the situation of increasing problems concerning with the environmental quality in forest land and the long-term productivity of forest,it was significant to develop and improve management strategies that maintain the function and protect the resources of soils.Changes of forest management strategies may lead to change in SOC quantity and quality.It was necessary to maintain a high SOC status for long-term land use due to the multiple beneficial effects of SOC on the soil nutrient states,structure and water holding capacity etc.The effects of different silvicultural practices on soil organic carbon were still poorly approached.Thus we performed the study on changes of soil organic carbon(SOC) in the Moso(Phyllostachys pubescens) stands among the long-term conversion of extensively managed and intensively managed in Fuyang County,Zhejiang province,where Moso were widely distributed.Bamboo stands of different management types,which were established in 1984,were designed to investigate the effects of intensive management on SOC.The results showed: total organic carbon(TOC),readily oxidation carbon(ROC),water soluble organic carbon(WSOC) and light fraction organic matter(LFOM) in 0—10cm soil layer were significantly decreased by 8.64%,14.11%,8.29% and 29.70%(0—20cm) respectively after intensive management.The vertical features of different soil organic carbon under two management types of bamboo stands were observed in decline trends with increasing of soil depths,while both of the decline scopes were different.The profile distribution of soil ROC and WSOC varied to some extent since intensive practice.These different fractions of labile organic carbon mentioned above were all interrelated,significantly or extremely significantly,and they also were well correlated with total N,hydrolysis N,available K,Ca,Mg(WSOC wasn′t significantly correlated with available P),while LFOM wasn′t significantly related to other soil nutrients except available Ca.Moreover after intensive management,availability of ROC,availability of WSOC and activity of carbon pool were decreased with significant level in part of soil layers.Therefore,to improve soil quality and achieve the goal of sustainable management of bamboo stands,a mixture of organic and inorganic manures with the proper ratio in bamboo stands should be applied under the conditions of intensive management,combined with ploughing,weeding,reasonable bamboo leaving and bamboo cutting,which could fulfill a high yield of bamboo shoot and bamboo culm,and maintain the ecological function of bamboo stands. The variation of results observed in soil C pool responded to different silvicultural methods in different studies may be due to variation in site types,original soil condition,timing and realization of forest managements,climatic factors,and/or interaction of some or all of these.However,this study along with the meta-analysis suggested that a categorical assumption of soil C loss under different forest management was unwarranted.Certainly,it was still needed to identify management methods that were most likely to cause or prevent SOC loss by further study.On the other hand,hydric soils may be much more sensitive to changes in temperature and moisture regimes as a result of silvicultural practices.Because the amount of the organic matter pool in mineral soils represents the potential to supply nitrogen,it is desirable to maintain organic matter in bamboo stands.

To improve the fuze-warhead coordination efficiency, the working principle of gun-launched electron-magnetic pulse bomb was analyzed, and the coordination process in actual ballistics was divided into two stages. Stage 1: the killing area model was built to analyze the optimum burst point, and by introducing damage parameters, this stages coordination efficiency was characterized by damage rate. Stage 2: the best initiation timing model was built, the timing error spreading was calculated using small deviation method, and the coordination efficiency was characterized by the degree of seed current closer to its maximum. Based on the analysis above, the calculation model of coordination efficiency was summarized, and some technical methods were given.