In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow sta...In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.展开更多
Psidium guajava Linn.(family Myrtaceae),is commonly known as guava.Guava is consumed in large quantities throughout the world due to its ease of cultivation and high nutritional value.As an important perennial fruit t...Psidium guajava Linn.(family Myrtaceae),is commonly known as guava.Guava is consumed in large quantities throughout the world due to its ease of cultivation and high nutritional value.As an important perennial fruit tree distributed around the world,guava has been widely used to manage various diseases in traditional medicine.Guava has been shown significant bioactivity such as antioxidant,anti-inflammatory,immunomodulatory,antimicrobial,antidiabetic,and anticancer properties.A large number of studies indicated that guava contains various type of phytochemicals including monoterpenes,sesquiterpenes,triterpenes,phenolics,and meroterpenoids.Among them,meroterpenoids are characteristic components of guava,which are hybrid of acylphloroglucinol with terpenoids(monoterpenes,sesquiterpenes).Modern pharmacological investigations showed intricate Psidium meroterpenoids possess a wide range of bioactivities.Although a large and growing body of literatures have investigated the Psidium meroterpenoids isolated from guava,a comprehensive review of Psidium meroterpenoids and their bioactivities has not been conducted.Therefore,this review provides a comprehensive compile of 75 meroterpenoids isolated from guava and their bioactivities between 2007 and May 2022.Furthermore,the possible biosynthesis way and future directions of Psidium meroterpenoids have also been discussed.展开更多
文摘In Fused Filament Fabrication(FFF),the state of material flow significantly influences printing outcomes.However,online monitoring of these micro-physical processes within the extruder remains challenging.The flow state is affected by multiple parameters,with temperature and volumetric flow rate(VFR)being the most critical.The study explores the stable extrusion of flow with a highly sensitive acoustic emission(AE)sensor so that AE signals generated by the friction in the annular region can reflect the flow state more effectively.Nevertheless,the large volume and broad frequency range of the data present processing challenges.This study proposes a method that initially selects short impact signals and then uses the Fast Kurtogram(FK)to identify the frequency with the highest kurtosis for signal filtration.The results indicate that this approach significantly enhances processing speed and improves feature extraction capabilities.By correlating AE characteristics under various parameters with the quality of extruded raster beads,AE can monitor the real-time state of material flow.This study offers a concise and efficient method for monitoring the state of raster beads and demonstrates the potential of online monitoring of the flow states.
基金This work was financially supported by the National Natural Science Foundation of China(U1802287 and 32170408)the Ten Thousand Talents Plan of Yunnan Province for Industrial Technology Leading Talents(YNWR-CYJS-2019-011)+1 种基金the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001)the State Key Laboratory of Phytochemistry and Plant Resources in West China(P2019-ZZ02).
文摘Psidium guajava Linn.(family Myrtaceae),is commonly known as guava.Guava is consumed in large quantities throughout the world due to its ease of cultivation and high nutritional value.As an important perennial fruit tree distributed around the world,guava has been widely used to manage various diseases in traditional medicine.Guava has been shown significant bioactivity such as antioxidant,anti-inflammatory,immunomodulatory,antimicrobial,antidiabetic,and anticancer properties.A large number of studies indicated that guava contains various type of phytochemicals including monoterpenes,sesquiterpenes,triterpenes,phenolics,and meroterpenoids.Among them,meroterpenoids are characteristic components of guava,which are hybrid of acylphloroglucinol with terpenoids(monoterpenes,sesquiterpenes).Modern pharmacological investigations showed intricate Psidium meroterpenoids possess a wide range of bioactivities.Although a large and growing body of literatures have investigated the Psidium meroterpenoids isolated from guava,a comprehensive review of Psidium meroterpenoids and their bioactivities has not been conducted.Therefore,this review provides a comprehensive compile of 75 meroterpenoids isolated from guava and their bioactivities between 2007 and May 2022.Furthermore,the possible biosynthesis way and future directions of Psidium meroterpenoids have also been discussed.
