Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus i...Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.展开更多
Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demand...Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demands on the flexibility of production.Material requirements planning(MRP)is a modern enterprise management method based on basic databill of materials(BOM).For order-driven SMEs,MRP not only helps enterprises to complete material delivery in a timely manner,but also provides flexibility to meet customer needs.Standardization and MRP complement each other in enterprise operation,and they are effective in solving problems such as untimely material supply,undetermined procurement timing,and supply chain system jams.By studying the standardization application of MRP in enterprises,the article not only optimizes the standardization management system of enterprises,but also contributes to the high-quality development of SMEs.展开更多
基金supported by the National Key R&D Pro-gram of China(No.2020YFD0900203)the China Agricul-ture Research System of MOF and MARAthe K.C.Wong Magna Fund in Ningbo University。
文摘Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.
文摘Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demands on the flexibility of production.Material requirements planning(MRP)is a modern enterprise management method based on basic databill of materials(BOM).For order-driven SMEs,MRP not only helps enterprises to complete material delivery in a timely manner,but also provides flexibility to meet customer needs.Standardization and MRP complement each other in enterprise operation,and they are effective in solving problems such as untimely material supply,undetermined procurement timing,and supply chain system jams.By studying the standardization application of MRP in enterprises,the article not only optimizes the standardization management system of enterprises,but also contributes to the high-quality development of SMEs.
