This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An...This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.展开更多
A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized d...A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized design was established with three replications and five treatments, i.e., NO-3-N/NH4+-N of 100/0, 75/25, 50/50, 25/75 and 0/100. Results showed that 25% replacement of NO3--N by NH4+-N significantly (P = 0.05) improved fresh and dry weight, revealing that a proper percentage of NH4+-N was important for tomato nitrogen nutrition. This could increase the plant growth even though tomato was a crop that preferred nitrate nutrition. Also an increase in the proportion of NH4+-N in the nutrient solution led to a significant decrease (P = 0.05) in malate, citrate and fumarate. However, the 25% NH4+-N plus 75% NO3--N treatment had no significant effect (P = 0.05) on the 2-ketoglutarate, succinate or oxalic acid content, showing that only some organic acids in tomato plants were affected. Only pyruvate increased significantly (P = 0.05), and it only increased for 25% and 50% replacement of NO3--N by NH4+-N. Metabolism of these organic acids, especially malate, citrate and fumarate, should be further studied at the molecular level in vegetables applied with different nitrogen forms.展开更多
The Minnesota Nutrient Management Strategy has identified waters with the highest amounts of nutrients that could potentially enter the Mississippi River.Mower County contains the headwaters of the Cedar River Basin,a...The Minnesota Nutrient Management Strategy has identified waters with the highest amounts of nutrients that could potentially enter the Mississippi River.Mower County contains the headwaters of the Cedar River Basin,a large nutrient loading basin in the upper Mississippi River Basin.Joint efforts of the UMN(University of Minnesota),the Nature Conservancy,and Mower County,MN implemented alternative agricultural ditch designs to improve water management.Designs consisted of a TSD(Two-Stage Ditch),a rock trench,a rock inlet,and two in-ditch linear treatment systems.These features were implemented to increase ditch stability and to reduce the loading of sediment and nutrients.Important costs were the possible removal of productive ag-land,construction costs,and the break-even discount(interest)rates.Benefits included lower maintenance cost,reduced sediment and phosphorus loads with more stable ditches,and enhanced removal of NO_(3)-N(Nitrate-Nitrogen).Results suggest costs of the TSD construction may be supplemented with subsidies to break-even with conventional ditch design costs.Subsidies based on NO_(3)-N removal show the TSD compares well to other NO_(3)-N best management practices.The break-even NO_(3)-N removal costs vary greatly but are lowest when the floodplain bench is inundated for longer time periods and when the discount rate,cleanout interval of the conventional design,and construction costs of the TSD are low.展开更多
文摘This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.
基金Project supported by the National Natural Science Foundation of China (No. 30270790) and National Post-doctoral Foundation of China (No. 2003033494).
文摘A hydroponic experiment was conducted to study the effect of partial replacement of NO-3-N by NH4+-N on the seedling growth and organic acid content of tomato (Lycopersicon esculentum Mill.). A completely randomized design was established with three replications and five treatments, i.e., NO-3-N/NH4+-N of 100/0, 75/25, 50/50, 25/75 and 0/100. Results showed that 25% replacement of NO3--N by NH4+-N significantly (P = 0.05) improved fresh and dry weight, revealing that a proper percentage of NH4+-N was important for tomato nitrogen nutrition. This could increase the plant growth even though tomato was a crop that preferred nitrate nutrition. Also an increase in the proportion of NH4+-N in the nutrient solution led to a significant decrease (P = 0.05) in malate, citrate and fumarate. However, the 25% NH4+-N plus 75% NO3--N treatment had no significant effect (P = 0.05) on the 2-ketoglutarate, succinate or oxalic acid content, showing that only some organic acids in tomato plants were affected. Only pyruvate increased significantly (P = 0.05), and it only increased for 25% and 50% replacement of NO3--N by NH4+-N. Metabolism of these organic acids, especially malate, citrate and fumarate, should be further studied at the molecular level in vegetables applied with different nitrogen forms.
文摘The Minnesota Nutrient Management Strategy has identified waters with the highest amounts of nutrients that could potentially enter the Mississippi River.Mower County contains the headwaters of the Cedar River Basin,a large nutrient loading basin in the upper Mississippi River Basin.Joint efforts of the UMN(University of Minnesota),the Nature Conservancy,and Mower County,MN implemented alternative agricultural ditch designs to improve water management.Designs consisted of a TSD(Two-Stage Ditch),a rock trench,a rock inlet,and two in-ditch linear treatment systems.These features were implemented to increase ditch stability and to reduce the loading of sediment and nutrients.Important costs were the possible removal of productive ag-land,construction costs,and the break-even discount(interest)rates.Benefits included lower maintenance cost,reduced sediment and phosphorus loads with more stable ditches,and enhanced removal of NO_(3)-N(Nitrate-Nitrogen).Results suggest costs of the TSD construction may be supplemented with subsidies to break-even with conventional ditch design costs.Subsidies based on NO_(3)-N removal show the TSD compares well to other NO_(3)-N best management practices.The break-even NO_(3)-N removal costs vary greatly but are lowest when the floodplain bench is inundated for longer time periods and when the discount rate,cleanout interval of the conventional design,and construction costs of the TSD are low.
