Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w...Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.展开更多
Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)...Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.展开更多
Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for es...Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for estimating organic matter(OM)composition,and can thus serve as a proxy for conventional chemical oxygen demand(COD_(Mn))measurements,which are considered as imprecise and environmentally unfriendly.Hence,we conducted a field campaign across 30 lakes in Wuhan's metropolitan area,collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_(Mn)using DOM optical measurements combined with parallel factor(PARAFAC)analysis.The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels(TSLs).Fluorescence components C1-C3 and C5,fluorescence index(FI),and absorption at 254 nm(α_(254)),increased as TSL increased,while the DOM spectral slope(SR)decreased.COD_(Mn)was positively and significantly correlated with fluorescence components C1-C3 and C5,freshness index(β/α),autochthonous index(BIX),humification index(HIX),α_(254),the ratio ofα_(250)toα_(365)(E2/E3)while being negatively correlated with SR.Parametersα_(254),C1,C3,C4,FI,β/α,and HIX were identified as key predictors of COD_(Mn).The multiple linear regression model successfully predicted COD_(Mn)(r^(2)=0.63,p<0.01,n=1113)and demonstrated superior performance in mesotrophic lakes.These findings highlight the potential for establishing high-frequency,continuous,and multi-regional COD monitoring programs.展开更多
In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the com...In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.展开更多
The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp....The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp.,Isochrysis galbana,and Tetraselmis helgolandica—distinguished by their pigments.We exposed them to seven light spectra,including white(control),red,orange,green,blue,violet,and full spectrum.The results showed distinct responses in the three microalgae to varying light spectra.Optimal growth occurred under blue,violet,and white lights for Chaetoceros sp.,Ⅰ.galbana,and T.helgolandica,respectively,while orange,red,and green lights inhibited growth.Notably,green light significantly increased the protein content in all three microalgae.Carbohydrate and lipid content exhibited species-specific responses:the highest carbohydrate accumulation was achieved for Chaetoceros sp.under red light(73.27±1.45 mg/g),Ⅰ.galbana under orange light(122.89±12.28 mg/g),and T.helgolandica under blue light(43.62±2.79 mg/g).Meanwhile,the highest lipid content was obtained under violet light for Chaetoceros sp.andⅠ.galbana(250.80±7.27 and 320.23±5.75 mg/g,respectively),and under green light for T.helgolandica(255.12±31.19 mg/g).Furthermore,violet light greatly promoted the accumulation of polyunsaturated fatty acids in all three microalgae.Specific pigment compositions also responded to variations in light spectra.For instance,the diadinoxanthin content in Chaetoceros sp.increased significantly under orange light(194.77±13.78μg/g),while chlorophyll-a content inⅠ.galbana increased significantly under violet and blue lights((88.84±33.46)-(141.38±1.64)μg/g),and in T.helgolandica under red,green,and blue lights((1485.04±190.46)-(1886.60±387.42)μg/g).Additionally,Ⅰ.galbana exhibited the highest fucoxanthin,diadinoxanthin,andβ-carotene contents under white light.In conclusion,our results highlight the species-specific impact of light spectra on microalgae growth and nutrients,providing valuable guidance for flexible application of light spectra in microalgal production to enhance yields and target specific nutrients.展开更多
Glutinous rice(Oryza sativa var.glutinosa)stands out as one of the most popular rice varieties globally,amidst thousands of rice cultivars.Its increasing popularity is attributed to its rich nutritional compositions a...Glutinous rice(Oryza sativa var.glutinosa)stands out as one of the most popular rice varieties globally,amidst thousands of rice cultivars.Its increasing popularity is attributed to its rich nutritional compositions and health benefits.This review aims to summarize the nutritional compositions,volatile compounds,and health benefits of glutinous rice.Further,in-depth studies are necessary to explore the utilization of glutinous rice in enhancing processing technologies and developing new food products.Glutinous rice has been shown to possess numerous health benefits,including antioxidant activity,bioactive compounds,anti-cancer properties,anti-inflammatory effects,anti-diabetic potential,and cholesterol-lowering effects.Besides its nutritional compositions,the major volatile compounds identified in glutinous rice could serve as a functional food for human consumption.Emerging processing technologies related to glutinous rice are elaborated to improve the latest developments for incorporating them into various food products.展开更多
Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been dee...Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been deepend.This paper aims to systematically summarize the chemical compositions and pharmacological effects of X.strumarium,in order to provide theoretical basis and reference for further exploration in its clinical application and drug development.展开更多
文摘Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.
基金financially supported by the Fundamental Research Program of the Russian Academy of Sciences for the Semenov Research Center of Chemical Physics,Russian Academy of Sciences。
文摘Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.
基金This study was funded by Wuhan Institute of Technology(Grant Nos.24QD26,21QD02,22QD64)National Natural Science Foundation of China(Grant No.32102823).
文摘Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for estimating organic matter(OM)composition,and can thus serve as a proxy for conventional chemical oxygen demand(COD_(Mn))measurements,which are considered as imprecise and environmentally unfriendly.Hence,we conducted a field campaign across 30 lakes in Wuhan's metropolitan area,collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_(Mn)using DOM optical measurements combined with parallel factor(PARAFAC)analysis.The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels(TSLs).Fluorescence components C1-C3 and C5,fluorescence index(FI),and absorption at 254 nm(α_(254)),increased as TSL increased,while the DOM spectral slope(SR)decreased.COD_(Mn)was positively and significantly correlated with fluorescence components C1-C3 and C5,freshness index(β/α),autochthonous index(BIX),humification index(HIX),α_(254),the ratio ofα_(250)toα_(365)(E2/E3)while being negatively correlated with SR.Parametersα_(254),C1,C3,C4,FI,β/α,and HIX were identified as key predictors of COD_(Mn).The multiple linear regression model successfully predicted COD_(Mn)(r^(2)=0.63,p<0.01,n=1113)and demonstrated superior performance in mesotrophic lakes.These findings highlight the potential for establishing high-frequency,continuous,and multi-regional COD monitoring programs.
基金Supported by The Innovation Fund of Postgraduate,Sichuan University of Science&Engineering(Y2024336)NSF of Sichuan Province(2023NSFSC0065).
文摘In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.
基金Supported by the National Natural Science Foundation of China(No.32102763)the Ningbo Science and Technology Research Projects+3 种基金China(No.2019B10006)the earmarked fund(No.CARS-49)the Ningbo Science and Technology Research ProjectsChina(No.2024Z276)。
文摘The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp.,Isochrysis galbana,and Tetraselmis helgolandica—distinguished by their pigments.We exposed them to seven light spectra,including white(control),red,orange,green,blue,violet,and full spectrum.The results showed distinct responses in the three microalgae to varying light spectra.Optimal growth occurred under blue,violet,and white lights for Chaetoceros sp.,Ⅰ.galbana,and T.helgolandica,respectively,while orange,red,and green lights inhibited growth.Notably,green light significantly increased the protein content in all three microalgae.Carbohydrate and lipid content exhibited species-specific responses:the highest carbohydrate accumulation was achieved for Chaetoceros sp.under red light(73.27±1.45 mg/g),Ⅰ.galbana under orange light(122.89±12.28 mg/g),and T.helgolandica under blue light(43.62±2.79 mg/g).Meanwhile,the highest lipid content was obtained under violet light for Chaetoceros sp.andⅠ.galbana(250.80±7.27 and 320.23±5.75 mg/g,respectively),and under green light for T.helgolandica(255.12±31.19 mg/g).Furthermore,violet light greatly promoted the accumulation of polyunsaturated fatty acids in all three microalgae.Specific pigment compositions also responded to variations in light spectra.For instance,the diadinoxanthin content in Chaetoceros sp.increased significantly under orange light(194.77±13.78μg/g),while chlorophyll-a content inⅠ.galbana increased significantly under violet and blue lights((88.84±33.46)-(141.38±1.64)μg/g),and in T.helgolandica under red,green,and blue lights((1485.04±190.46)-(1886.60±387.42)μg/g).Additionally,Ⅰ.galbana exhibited the highest fucoxanthin,diadinoxanthin,andβ-carotene contents under white light.In conclusion,our results highlight the species-specific impact of light spectra on microalgae growth and nutrients,providing valuable guidance for flexible application of light spectra in microalgal production to enhance yields and target specific nutrients.
基金the Ministry of Higher Education,Malaysia for financial support via the Transdisciplinary Research Grant Scheme Project(Grant No.TRGS/1/2020/UPM/02/7)。
文摘Glutinous rice(Oryza sativa var.glutinosa)stands out as one of the most popular rice varieties globally,amidst thousands of rice cultivars.Its increasing popularity is attributed to its rich nutritional compositions and health benefits.This review aims to summarize the nutritional compositions,volatile compounds,and health benefits of glutinous rice.Further,in-depth studies are necessary to explore the utilization of glutinous rice in enhancing processing technologies and developing new food products.Glutinous rice has been shown to possess numerous health benefits,including antioxidant activity,bioactive compounds,anti-cancer properties,anti-inflammatory effects,anti-diabetic potential,and cholesterol-lowering effects.Besides its nutritional compositions,the major volatile compounds identified in glutinous rice could serve as a functional food for human consumption.Emerging processing technologies related to glutinous rice are elaborated to improve the latest developments for incorporating them into various food products.
基金supported by National Nature Science Foundation of China(81973284)Scientific Research Foundation of the Education Department of Liaoning Province(LJKZ0944).
文摘Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been deepend.This paper aims to systematically summarize the chemical compositions and pharmacological effects of X.strumarium,in order to provide theoretical basis and reference for further exploration in its clinical application and drug development.
