Short_term batch cultures were used to measure the phosphate_dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results wer...Short_term batch cultures were used to measure the phosphate_dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results were fitted to the Monod model. U. pertusa had a lower half_saturation constant and maximum growth rate, which were 0.016 μmol/L and 0.16 d -1 respectively, while the growth kinetics of T. subcordiformis were 0.021 μmol/L and 0.83 d -1 . Long_term semicontinuous nutrient competition experiments were performed between T. subcordiformis and U. pertusa under phosphate limitation in laboratory. Loss rates were manipulated to get the same or different resource requirement values ( R * ) of the two species. Comparison between the theoretical predictions derived from Monod kinetics and the outcome of competition experiments indicated that the Monod model could predict the results only when the R * values of the two species were significantly different, and T. subcordiformis displaced U. pertusa when they had the same resource requirements. The Monod model can only partly predict the competition results between microalga and macroalga.展开更多
Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development（RD）investment subsidies and product subsidies for dom...Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development（RD）investment subsidies and product subsidies for domestic firms provided by the government, and the RD subsidy policy of domestic firms in competition with foreign firms is analyzed.The equilibrium output, RD investment of the domestic firm, social welfare and the value of government subsidies are derived, in the case of the two policies, RD investment subsidies and product subsidies for domestic firms, provided by the government. The results show that, the equilibrium output and the optimal social welfare under the RD investment subsidy policy are both less than those under the product subsidy policy; the optimal RD investment under the RD investment subsidy policy is less than that under the product subsidy policy; and the RD product subsidy has a more obvious incentive effect on firm RD investment. Under the background of the leading edge of technology of foreign firms, the product subsidy policy drawn up by the government to encourage RD innovation of domestic firms is more effective than the RD investment subsidy policy.展开更多
The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for stu...The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.展开更多
Climate change is an alarming global challenge, particularly affecting the least developed countries (LDCs) including Liberia. These countries, located in regions prone to unpredictable temperature and precipitation c...Climate change is an alarming global challenge, particularly affecting the least developed countries (LDCs) including Liberia. These countries, located in regions prone to unpredictable temperature and precipitation changes, are facing significant challenges, particularly in climate-sensitive sectors such as mining and agriculture. LDCs need more resilience to adverse climate shocks but have limited capacity for adaptation compared to other developed and developing nations. This paper examines Liberia’s susceptibility to climate change as a least developed country, focusing on its exposure, sensitivity, and adaptive capacity. It provides an overview of LDCs and outlines the global distribution of carbon dioxide emissions. The paper also evaluates specific challenges that amplify Liberia’s vulnerability and constrain sustainable adaptation, providing insight into climate change’s existing and potential effects. The paper emphasizes the urgency of addressing climate impacts on Liberia and calls for concerted local and international efforts for effective and sustainable mitigation efforts. It provides recommendations for policy decisions and calls for further research on climate change mitigation and adaptation.展开更多
文摘Short_term batch cultures were used to measure the phosphate_dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results were fitted to the Monod model. U. pertusa had a lower half_saturation constant and maximum growth rate, which were 0.016 μmol/L and 0.16 d -1 respectively, while the growth kinetics of T. subcordiformis were 0.021 μmol/L and 0.83 d -1 . Long_term semicontinuous nutrient competition experiments were performed between T. subcordiformis and U. pertusa under phosphate limitation in laboratory. Loss rates were manipulated to get the same or different resource requirement values ( R * ) of the two species. Comparison between the theoretical predictions derived from Monod kinetics and the outcome of competition experiments indicated that the Monod model could predict the results only when the R * values of the two species were significantly different, and T. subcordiformis displaced U. pertusa when they had the same resource requirements. The Monod model can only partly predict the competition results between microalga and macroalga.
基金The Special Project of Innovative Methods and Work Funded by Ministry of National Science and Technology of China(No.2013IM030600)
文摘Taking the advanced technology of the foreign firm into account, a mixed duopoly three-stage game model is established in the context of research and development（RD）investment subsidies and product subsidies for domestic firms provided by the government, and the RD subsidy policy of domestic firms in competition with foreign firms is analyzed.The equilibrium output, RD investment of the domestic firm, social welfare and the value of government subsidies are derived, in the case of the two policies, RD investment subsidies and product subsidies for domestic firms, provided by the government. The results show that, the equilibrium output and the optimal social welfare under the RD investment subsidy policy are both less than those under the product subsidy policy; the optimal RD investment under the RD investment subsidy policy is less than that under the product subsidy policy; and the RD product subsidy has a more obvious incentive effect on firm RD investment. Under the background of the leading edge of technology of foreign firms, the product subsidy policy drawn up by the government to encourage RD innovation of domestic firms is more effective than the RD investment subsidy policy.
文摘The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.
文摘Climate change is an alarming global challenge, particularly affecting the least developed countries (LDCs) including Liberia. These countries, located in regions prone to unpredictable temperature and precipitation changes, are facing significant challenges, particularly in climate-sensitive sectors such as mining and agriculture. LDCs need more resilience to adverse climate shocks but have limited capacity for adaptation compared to other developed and developing nations. This paper examines Liberia’s susceptibility to climate change as a least developed country, focusing on its exposure, sensitivity, and adaptive capacity. It provides an overview of LDCs and outlines the global distribution of carbon dioxide emissions. The paper also evaluates specific challenges that amplify Liberia’s vulnerability and constrain sustainable adaptation, providing insight into climate change’s existing and potential effects. The paper emphasizes the urgency of addressing climate impacts on Liberia and calls for concerted local and international efforts for effective and sustainable mitigation efforts. It provides recommendations for policy decisions and calls for further research on climate change mitigation and adaptation.
