The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-a...The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-aided design(TCAD)simulation.Comparative analysis of the heavy-ion irradiation effects on three device structures reveals distinct susceptibility characteristics.The gate oxide region is identified as the most sensitive position in planar devices,while trench and doubletrench structures exhibit no localized sensitive regions.Furthermore,the single-event susceptibility demonstrates strong depth dependence across all three structures,with enhanced vulnerability observed at greater ion penetration depths.展开更多
近年来随着无人机产业的迅猛发展,视觉定位技术已广泛应用于低成本轻量化的定位系统中,然而当无人机在水面等弱纹理区域飞行时,场景视觉特征稀疏且差异小,导致图像误匹配率激增,定位估计发散严重,限制了视觉定位技术在水域环境下的应用...近年来随着无人机产业的迅猛发展,视觉定位技术已广泛应用于低成本轻量化的定位系统中,然而当无人机在水面等弱纹理区域飞行时,场景视觉特征稀疏且差异小,导致图像误匹配率激增,定位估计发散严重,限制了视觉定位技术在水域环境下的应用。针对该问题提出了一种基于水纹识别的视觉定位技术(visual positioning technique based on water pattern recognition,WPRVP)。首先通过提取水纹多粒度相关特征得到相邻图像之间局部和全局的匹配关系;然后将匹配信息嵌入循环网络迭代处理,由粗到细逐步提高水纹图像的匹配精度;最后基于多视图几何约束进行匹配筛选和运动建模,实现了鲁棒的定位估计。实验结果表明,相比现有的图像匹配和视觉定位方法,WPRVP能够应用于水域环境且能保持更高的匹配与定位精度,能够为导航设备在水域场景下提供一个低成本高精度的导航信息源,辅助无人机执行水面飞行任务。展开更多
[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical sim...[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical simulations and dynamic analysis methods,this study systematically investigates the coupled dynamic response characteristics during the cage-carrier vessel separation process to reveal its dynamic evolution patterns and key influence mechanisms.[Method]Based on potential flow theory,a fully coupled dynamic analysis model of crane vessel-net cage-semi-submersible barge was established for a marine ranch project in Guangdong.The complete lifting process was dynamically simulated using SESAM software.Five typical operating sea states were configured to investigate the influence of wave parameters on the system's motion response under combined wave-current-wind actions.[Result]The results demonstrate that wave period dominates the system stability.Under short-period conditions,the system maintains stable motion with relatively small horizontal relative displacements,while long-period conditions excite low-frequency resonance,leading to significant slow-drift motions.Vertical response analysis reveals that long-period waves cause severe relative displacement fluctuations between the cage and semi-submersible vessel,with actual displacement amplitudes doubling the preset safety target of 2.045 m.Quantitative analysis further indicates that when significant wave height increases from 1.0 m to 1.5 m,the actual displacement amplitude increases by approximately 20%relative to the target displacement of 2.045 m,demonstrating that its influence is significantly weaker than the displacement variations induced by wave period changes.The complete dynamic simulation successfully captures the continuous dynamic response characteristics during the lifting process.[Conclusion]This research clarifies the influence mechanisms of wave parameters on the cage lifting process,identifying wave period as the crucial factor for operational safety.An operation window assessment method incorporating multi-body coupling effects is established,proposing a safety criterion with peak period not exceeding six seconds as the core requirement.The findings provide theoretical foundation for safe installation of marine ranch net cages and offer valuable references for similar offshore lifting operations.展开更多
Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isol...Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil. Among these isolates, seven showed strong biofilm-forming capacity. The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudornonas sp., Pseudomonas putida, Aeromonas caviae, Bacillus cereus, Pseudornonas plecoglossicida, Aeromonas hydrophila, and Comamonas testosteroni. The biofilm-forming capacity was closely related with flagella, exopolysaccharide, and extracellular protein. According to the coefficient of determination, the relative importance of the five biological characteristics to biofilm formation was, in order from greatest to least, exopolysaccharide 〉 flagella 〉 N-acyl-homoserine lactones （AHLs） signaling molecules 〉 extracellular protein 〉 swarming motility.展开更多
Salidroside(SAL)is a phenolic substance with high solubility and low permeability,which make it easy to cause the efflux effect of P-glycoprotein and degradation of intestinal flora,resulting in lower bioavailability....Salidroside(SAL)is a phenolic substance with high solubility and low permeability,which make it easy to cause the efflux effect of P-glycoprotein and degradation of intestinal flora,resulting in lower bioavailability.The aim of this study was to develop and optimize a water-in-oil nanoemulsion of SAL(w/o SAL-N)to explore its suitability in oral drug delivery systems.In this work,SAL-N was successfully prepared by water titration method at K_(m)=1 to construct the pseudo-ternary phase diagrams.Physical characterization including the average viscosity,pH,refractive index,particle size,PDI,TEM,DSC,the content of SAL,and stability study were performed.It was evaluated for drug release in vitro and pharmacokinetic studies in vivo.The optimized nanoemulsion formulation consisted of Labrafil M 1944 CS(63%),Span-80/Tween-80/EtOH(27%)and 200 mg·mL^(-1) SAL solution(SAL-SOL)(10%).Low viscosity and suitable pH were expected for the nanoemulsion.The spherical morphology and nanoscale size of SAL-N enhanced the stability of the nanoemulsion system.In vitro drug release showed that SAL-N had a better controlled release property than SAL-SOL at earlier time points.The pharmacokinetic studies exhibited that SAL-N had significantly higher in t_(1/2)(2.11-fold),AUC_(0-48 h)(1.75-fold)and MRT0-48 h(2.63-fold)than SAL-SOL(P<0.01).The w/o SAL-N prepared in this work can be effectively delivered via the oral route.It can be seen w/o nanoemulsion is a strategy for the drug with polyphenols to delay the release,enhance oral absorption and reduce metabolic rate.展开更多
基金National Key Research and Development Program of China(2023YFA1609000)National Natural Science Foundation of China(62474190,U22B2043,U2267210)。
文摘The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-aided design(TCAD)simulation.Comparative analysis of the heavy-ion irradiation effects on three device structures reveals distinct susceptibility characteristics.The gate oxide region is identified as the most sensitive position in planar devices,while trench and doubletrench structures exhibit no localized sensitive regions.Furthermore,the single-event susceptibility demonstrates strong depth dependence across all three structures,with enhanced vulnerability observed at greater ion penetration depths.
文摘近年来随着无人机产业的迅猛发展,视觉定位技术已广泛应用于低成本轻量化的定位系统中,然而当无人机在水面等弱纹理区域飞行时,场景视觉特征稀疏且差异小,导致图像误匹配率激增,定位估计发散严重,限制了视觉定位技术在水域环境下的应用。针对该问题提出了一种基于水纹识别的视觉定位技术(visual positioning technique based on water pattern recognition,WPRVP)。首先通过提取水纹多粒度相关特征得到相邻图像之间局部和全局的匹配关系;然后将匹配信息嵌入循环网络迭代处理,由粗到细逐步提高水纹图像的匹配精度;最后基于多视图几何约束进行匹配筛选和运动建模,实现了鲁棒的定位估计。实验结果表明,相比现有的图像匹配和视觉定位方法,WPRVP能够应用于水域环境且能保持更高的匹配与定位精度,能够为导航设备在水域场景下提供一个低成本高精度的导航信息源,辅助无人机执行水面飞行任务。
文摘[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical simulations and dynamic analysis methods,this study systematically investigates the coupled dynamic response characteristics during the cage-carrier vessel separation process to reveal its dynamic evolution patterns and key influence mechanisms.[Method]Based on potential flow theory,a fully coupled dynamic analysis model of crane vessel-net cage-semi-submersible barge was established for a marine ranch project in Guangdong.The complete lifting process was dynamically simulated using SESAM software.Five typical operating sea states were configured to investigate the influence of wave parameters on the system's motion response under combined wave-current-wind actions.[Result]The results demonstrate that wave period dominates the system stability.Under short-period conditions,the system maintains stable motion with relatively small horizontal relative displacements,while long-period conditions excite low-frequency resonance,leading to significant slow-drift motions.Vertical response analysis reveals that long-period waves cause severe relative displacement fluctuations between the cage and semi-submersible vessel,with actual displacement amplitudes doubling the preset safety target of 2.045 m.Quantitative analysis further indicates that when significant wave height increases from 1.0 m to 1.5 m,the actual displacement amplitude increases by approximately 20%relative to the target displacement of 2.045 m,demonstrating that its influence is significantly weaker than the displacement variations induced by wave period changes.The complete dynamic simulation successfully captures the continuous dynamic response characteristics during the lifting process.[Conclusion]This research clarifies the influence mechanisms of wave parameters on the cage lifting process,identifying wave period as the crucial factor for operational safety.An operation window assessment method incorporating multi-body coupling effects is established,proposing a safety criterion with peak period not exceeding six seconds as the core requirement.The findings provide theoretical foundation for safe installation of marine ranch net cages and offer valuable references for similar offshore lifting operations.
基金supported by the National Natural Science Foundation of China (No.30600016)the Environment Protection Department of Jiangsu Province,China (No.2004007)
文摘Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants. Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil. Among these isolates, seven showed strong biofilm-forming capacity. The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudornonas sp., Pseudomonas putida, Aeromonas caviae, Bacillus cereus, Pseudornonas plecoglossicida, Aeromonas hydrophila, and Comamonas testosteroni. The biofilm-forming capacity was closely related with flagella, exopolysaccharide, and extracellular protein. According to the coefficient of determination, the relative importance of the five biological characteristics to biofilm formation was, in order from greatest to least, exopolysaccharide 〉 flagella 〉 N-acyl-homoserine lactones （AHLs） signaling molecules 〉 extracellular protein 〉 swarming motility.
基金supported by Tianjin City High School Science Technology Fund Planning Project(No.2017KJ134)。
文摘Salidroside(SAL)is a phenolic substance with high solubility and low permeability,which make it easy to cause the efflux effect of P-glycoprotein and degradation of intestinal flora,resulting in lower bioavailability.The aim of this study was to develop and optimize a water-in-oil nanoemulsion of SAL(w/o SAL-N)to explore its suitability in oral drug delivery systems.In this work,SAL-N was successfully prepared by water titration method at K_(m)=1 to construct the pseudo-ternary phase diagrams.Physical characterization including the average viscosity,pH,refractive index,particle size,PDI,TEM,DSC,the content of SAL,and stability study were performed.It was evaluated for drug release in vitro and pharmacokinetic studies in vivo.The optimized nanoemulsion formulation consisted of Labrafil M 1944 CS(63%),Span-80/Tween-80/EtOH(27%)and 200 mg·mL^(-1) SAL solution(SAL-SOL)(10%).Low viscosity and suitable pH were expected for the nanoemulsion.The spherical morphology and nanoscale size of SAL-N enhanced the stability of the nanoemulsion system.In vitro drug release showed that SAL-N had a better controlled release property than SAL-SOL at earlier time points.The pharmacokinetic studies exhibited that SAL-N had significantly higher in t_(1/2)(2.11-fold),AUC_(0-48 h)(1.75-fold)and MRT0-48 h(2.63-fold)than SAL-SOL(P<0.01).The w/o SAL-N prepared in this work can be effectively delivered via the oral route.It can be seen w/o nanoemulsion is a strategy for the drug with polyphenols to delay the release,enhance oral absorption and reduce metabolic rate.
