The influence of additive Dy_(2)O_(3)on the magnetic properties of Nd_(16)(Fe_(0.96)Akl_(0.04))_(77)B_(7)has been investigated.It is shown that when the concentration is 4wt%the intrinsic coercivity_(i)H_(c)of the sin...The influence of additive Dy_(2)O_(3)on the magnetic properties of Nd_(16)(Fe_(0.96)Akl_(0.04))_(77)B_(7)has been investigated.It is shown that when the concentration is 4wt%the intrinsic coercivity_(i)H_(c)of the sintered magnets increases to 17850 Oe.展开更多
In order to analyze the spatial pattern of soil seed bank and its relation to environmental factors in lakeshore wetlands in Taihu Lake region,4 different sites in the lakeshore wetlands(A site at fleabane zone;B site...In order to analyze the spatial pattern of soil seed bank and its relation to environmental factors in lakeshore wetlands in Taihu Lake region,4 different sites in the lakeshore wetlands(A site at fleabane zone;B site at bush and grass zone;C site at crop zone;D site at natural reed zone) were established.Seed germination experiment was carried out and ordination technique(canonical correspondence analysis) was used in the study area.The results showed that totally 21 species(7 families) germinated from the seed banks.The seed bank density of 4 sites(A,B,C,and D sites)was(3 120 ± 1 581) ind./m2,(14 800 ± 5 049) ind./m2,(4 080 ± 1 760) ind./m2and(3 600 ± 2 882) ind./m2,respectively.With the deepening of the soil,the soil seed bank density of the vertical distribution showed a downward trend.Soil p H,soil moisture content,electric conductance,vegetation cover and soil bulk density all influenced the distribution of soil seed banks.Overall,soil moisture content had the greatest impact on the soil seed bank in lakeshore wetlands in Taihu Lake region.展开更多
The economic benefits and optimal rotation age of Larix kaempferi pulpwood plantation were analyzed under stochastic pulpwood price using real options approach in order to more effectively management to L.kaempferi pu...The economic benefits and optimal rotation age of Larix kaempferi pulpwood plantation were analyzed under stochastic pulpwood price using real options approach in order to more effectively management to L.kaempferi pulpwood plantation in northern sub-tropical alpine area.Flexible rotation age and threshold price to different stand age of different site index plantation were developed.The result indicated that:1) the optimal rotation age of L.kaempferi plantation in site index 15,17,19,21 was 25,23,21 and 19 a,respectively,as the current pulpwood price equals 500 yuan·m<sup>-3</sup>,and the shortest rotation age was 23,20,17 and 15 a when facing to better price;and 2) Wait option should be the optimum strategy in any pulpwood price level when the stand age is lower than the shortest rotation age.展开更多
Larix spp.wood is one of the major fast-growing tree species in China,which also has the most forest storage in the northeast of China.Several key properties modification methods and achievements of Larix spp.wood wer...Larix spp.wood is one of the major fast-growing tree species in China,which also has the most forest storage in the northeast of China.Several key properties modification methods and achievements of Larix spp.wood were summarized based on their characteristics.Technology problems of properties modification and new use prospect of modified Larix spp.wood were all discussed.展开更多
Flooding and anaerobic stress is one of the stress factors affecting mangroves.Mangrove species,differing considerably in their susceptibility to the stress,are distributed in different tidal elevation zones.Growing i...Flooding and anaerobic stress is one of the stress factors affecting mangroves.Mangrove species,differing considerably in their susceptibility to the stress,are distributed in different tidal elevation zones.Growing in regular seawater dipping and anoxic mud,mangroves have developed a set of adaptation mechanisms of flooding and anaerobic stress.This paper emphatically reviewed four physiological responses of mangroves to flooding and anaerobic stress,i.e.nutrition allocation, photosynthesis and respiration,carbon and nitrogen metabolism and antioxidant mechanism.Finally,it was proposed that studies should be further focused on the path of roots metabolism,non-structure carbohydrates and secondary metabolism of the mangroves under flooding and anaerobic condition.展开更多
文摘The influence of additive Dy_(2)O_(3)on the magnetic properties of Nd_(16)(Fe_(0.96)Akl_(0.04))_(77)B_(7)has been investigated.It is shown that when the concentration is 4wt%the intrinsic coercivity_(i)H_(c)of the sintered magnets increases to 17850 Oe.
基金Under the auspices of Special Forestry Project of Public Interests(201404305 and 200904001)
文摘In order to analyze the spatial pattern of soil seed bank and its relation to environmental factors in lakeshore wetlands in Taihu Lake region,4 different sites in the lakeshore wetlands(A site at fleabane zone;B site at bush and grass zone;C site at crop zone;D site at natural reed zone) were established.Seed germination experiment was carried out and ordination technique(canonical correspondence analysis) was used in the study area.The results showed that totally 21 species(7 families) germinated from the seed banks.The seed bank density of 4 sites(A,B,C,and D sites)was(3 120 ± 1 581) ind./m2,(14 800 ± 5 049) ind./m2,(4 080 ± 1 760) ind./m2and(3 600 ± 2 882) ind./m2,respectively.With the deepening of the soil,the soil seed bank density of the vertical distribution showed a downward trend.Soil p H,soil moisture content,electric conductance,vegetation cover and soil bulk density all influenced the distribution of soil seed banks.Overall,soil moisture content had the greatest impact on the soil seed bank in lakeshore wetlands in Taihu Lake region.
文摘The economic benefits and optimal rotation age of Larix kaempferi pulpwood plantation were analyzed under stochastic pulpwood price using real options approach in order to more effectively management to L.kaempferi pulpwood plantation in northern sub-tropical alpine area.Flexible rotation age and threshold price to different stand age of different site index plantation were developed.The result indicated that:1) the optimal rotation age of L.kaempferi plantation in site index 15,17,19,21 was 25,23,21 and 19 a,respectively,as the current pulpwood price equals 500 yuan·m<sup>-3</sup>,and the shortest rotation age was 23,20,17 and 15 a when facing to better price;and 2) Wait option should be the optimum strategy in any pulpwood price level when the stand age is lower than the shortest rotation age.
文摘Larix spp.wood is one of the major fast-growing tree species in China,which also has the most forest storage in the northeast of China.Several key properties modification methods and achievements of Larix spp.wood were summarized based on their characteristics.Technology problems of properties modification and new use prospect of modified Larix spp.wood were all discussed.
文摘Flooding and anaerobic stress is one of the stress factors affecting mangroves.Mangrove species,differing considerably in their susceptibility to the stress,are distributed in different tidal elevation zones.Growing in regular seawater dipping and anoxic mud,mangroves have developed a set of adaptation mechanisms of flooding and anaerobic stress.This paper emphatically reviewed four physiological responses of mangroves to flooding and anaerobic stress,i.e.nutrition allocation, photosynthesis and respiration,carbon and nitrogen metabolism and antioxidant mechanism.Finally,it was proposed that studies should be further focused on the path of roots metabolism,non-structure carbohydrates and secondary metabolism of the mangroves under flooding and anaerobic condition.
