In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy...In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.展开更多
为提高以大豆分离蛋白(Soybean protein isolate,SPI)为单一乳化剂所制备乳液的稳定性,本研究采用大豆分离蛋白和黄原胶(Xanthan gum,XG)为乳化剂,制备葵花籽油复合乳液(SPI-XG-e)和双层乳液(SPIe/XG),并重点考察了黄原胶浓度对乳液的...为提高以大豆分离蛋白(Soybean protein isolate,SPI)为单一乳化剂所制备乳液的稳定性,本研究采用大豆分离蛋白和黄原胶(Xanthan gum,XG)为乳化剂,制备葵花籽油复合乳液(SPI-XG-e)和双层乳液(SPIe/XG),并重点考察了黄原胶浓度对乳液的物理特性(平均粒径、Zeta-电位、浊度)及稳定性的影响。结果表明:在黄原胶浓度为1.0%时,双层乳液具有优良的物理特性,表现为更均匀的粒径分布,较小的平均粒径(0.63±0.03μm),较高的Zeta-电位绝对值(46.70±0.25 mV)以及低的离心稳定常数(0.70%±0.46%)。在对比复合乳液和双层乳液的稳定性时,后者显示出更好的环境适应性,特别是在1.0%的黄原胶浓度下制备的双层乳液,能够在4℃下存放7 d而不出现分层,并且在经过90℃的热处理后仍保持较高的Zeta-电位绝对值(44.47±0.31 mV),三次冻融循环后未出现絮凝等现象,具有较高的稳定性。本研究可为食品加工领域开发高稳定性水包油乳液提供参考和依据。展开更多
Aqueous zinc metal batteries(AZMBs)are promising candidates for renewable energy storage,yet their practical deployment in subzero environments remains challenging due to electrolyte freezing and dendritic growth.Alth...Aqueous zinc metal batteries(AZMBs)are promising candidates for renewable energy storage,yet their practical deployment in subzero environments remains challenging due to electrolyte freezing and dendritic growth.Although organic additives can enhance the antifreeze properties of electrolytes,their weak polarity diminishes ionic conductivity,and their flammability poses safety concerns,undermining the inherent advantages of aqueous systems.Herein,we present a cost-effective and highly stable Na_(2)SO_(4)additive introduced into a Zn(ClO_(4))2-based electrolyte to create an organic-free antifreeze electrolyte.Through Raman spectroscopy,in situ optical microscopy,densityfunctional theory computations,and molecular dynamics simulations,we demonstrate that Na+ions improve low-temperature electrolyte performance and mitigate dendrite formation by regulating uniform Zn^(2+)deposition through preferential adsorption and electrostatic interactions.As a result,the Zn||Zn cells using this electrolyte achieve a remarkable cycling life of 360 h at-40℃ with 61% depth of discharge,and the Zn||PANI cells retained an ultrahigh capacity retention of 91%even after 8000 charge/discharge cycles at-40℃.This work proposes a cost-effective and practical approach for enhancing the long-term operational stability of AZMBs in low-temperature environments.展开更多
In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocal...In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocally diffusive species and degenerately diffusive species.We prove that the traveling wavefronts are exponentially stable,when the initial perturbation around the traveling waves decays exponentially as x→-∞,but in other locations,the initial data can be arbitrarily large.The adopted methods are the weighted energy with the comparison principle and squeezing technique.展开更多
The Double Take column looks at a single topic from an African and Chinese perspective.This month,we discuss what makes a job meaningful.Look Beyond the Surface.What makes a job meaningful?The answer is far from unive...The Double Take column looks at a single topic from an African and Chinese perspective.This month,we discuss what makes a job meaningful.Look Beyond the Surface.What makes a job meaningful?The answer is far from universal.For some,it’s the stability of a pay cheque and a clear path for career growth.展开更多
基金Supported by the National Natural Science Foundation of China(12261018)Universities Key Laboratory of Mathematical Modeling and Data Mining in Guizhou Province(2023013)。
文摘In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.
基金financially supported by the National Natural Science Foundation of China(Grant No.52377206,52307237)Natural Science Foundation of Heilongjiang Province of China(YQ2024E046)Postdoctoral Science Foundation of Heilongjiang Province of China(LBH-TZ2413,LBH-Z23198)。
文摘Aqueous zinc metal batteries(AZMBs)are promising candidates for renewable energy storage,yet their practical deployment in subzero environments remains challenging due to electrolyte freezing and dendritic growth.Although organic additives can enhance the antifreeze properties of electrolytes,their weak polarity diminishes ionic conductivity,and their flammability poses safety concerns,undermining the inherent advantages of aqueous systems.Herein,we present a cost-effective and highly stable Na_(2)SO_(4)additive introduced into a Zn(ClO_(4))2-based electrolyte to create an organic-free antifreeze electrolyte.Through Raman spectroscopy,in situ optical microscopy,densityfunctional theory computations,and molecular dynamics simulations,we demonstrate that Na+ions improve low-temperature electrolyte performance and mitigate dendrite formation by regulating uniform Zn^(2+)deposition through preferential adsorption and electrostatic interactions.As a result,the Zn||Zn cells using this electrolyte achieve a remarkable cycling life of 360 h at-40℃ with 61% depth of discharge,and the Zn||PANI cells retained an ultrahigh capacity retention of 91%even after 8000 charge/discharge cycles at-40℃.This work proposes a cost-effective and practical approach for enhancing the long-term operational stability of AZMBs in low-temperature environments.
基金Supported by the National Natural Science Foundation of China(Grant No.12261081).
文摘In this paper,we are concerned with the stability of traveling wavefronts of a Belousov-Zhabotinsky model with mixed nonlocal and degenerate diffusions.Such a system can be used to study the competition among nonlocally diffusive species and degenerately diffusive species.We prove that the traveling wavefronts are exponentially stable,when the initial perturbation around the traveling waves decays exponentially as x→-∞,but in other locations,the initial data can be arbitrarily large.The adopted methods are the weighted energy with the comparison principle and squeezing technique.
文摘The Double Take column looks at a single topic from an African and Chinese perspective.This month,we discuss what makes a job meaningful.Look Beyond the Surface.What makes a job meaningful?The answer is far from universal.For some,it’s the stability of a pay cheque and a clear path for career growth.
