The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results...The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.展开更多
The development of highly efficient and inexpensive catalysts for oxygen evolving reactions （OERs） is extremely urgent for promoting the overall efficiency of water splitting. Herein we report the fabrication of a s...The development of highly efficient and inexpensive catalysts for oxygen evolving reactions （OERs） is extremely urgent for promoting the overall efficiency of water splitting. Herein we report the fabrication of a series of amorphous NiFeB nanoparticles with varying atomic ratios of Fe to （Ni ＋ Fe） （XFe） by a facile chemical-reduction method. The amorphous NiFeB （XFe=0.20） nanoparticles, combining the merits of in situ formation of borate-enriched NiFeOOH catalytic surface layers, intrinsic amorphous nanostructures, and an optimized degree of Fe doping, displayed highly active electrocatalytic performance towards the OER in a broad range of pH values （from alkaline to neutral conditions）. The catalyst exhibited a relatively low overpotential of 216 mV with a Tafel slope of 40 mWdec on Ni foam and 251 mV with a Tafel slope of 43 mV/dec on glassy carbon at 10 mA/cm2 in a 1 M KOH solution, demonstrating much greater OER efficiency than that of commercial RuO2. Long-term stability testing of the OER performance of NiFeB （XFe = 0.20） by chronoamperometry （overpotential （η） = 320 mV） over 200 h revealed no evidence of degradation. Facile, scalable synthesis and highly active water oxidation make the NiFeB nanoparticles very attractive for OER electrocatalysis.展开更多
Thoracic Surgery is a continuous evolving specialty. In the past, thoracic surgeons had to make large incisions in order to operate any pathology inside the chest. This often meant big, painful and ugly scars and long...Thoracic Surgery is a continuous evolving specialty. In the past, thoracic surgeons had to make large incisions in order to operate any pathology inside the chest. This often meant big, painful and ugly scars and long recovery times after surgery. But he history of thoracic surgery changed since the begining of video-assisted thoracoscoDic surgery （VATg3展开更多
挖掘时态关联规则的目的是为了发现带有时态信息的项集之间有趣的关系.由于数据库经常动态更新,时态关联规则的挖掘也应该适应数据库的更新.然而,现有的大多数算法不仅需要重新挖掘更新的数据库,浪费了大量的时间和效率,而且不能利用已...挖掘时态关联规则的目的是为了发现带有时态信息的项集之间有趣的关系.由于数据库经常动态更新,时态关联规则的挖掘也应该适应数据库的更新.然而,现有的大多数算法不仅需要重新挖掘更新的数据库,浪费了大量的时间和效率,而且不能利用已存在的规则定量地预测某些项的变化趋势.本文提出了一个基于多维时态关联规则的演化模糊推理预测建模算法(Evolving fuzzy inference model based on multidimensional temporal association rules,EFI-MTAR),主要优势是构建了一种基于多维时态关联规则的模糊推理建模算法(Fuzzy inference modeling algorithm based on multidimensional temporal association rules,FI-MTAR),实现了对时间序列的定量预测.此外,为了降低规则更新的代价和加快规则预测的速度,提出了概念漂移检测策略来处理时间序列数据以适应数据库的动态更新.实验结果表明了本文提出算法的有效性和准确性.展开更多
Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate...Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values Fn（t） for all t are always on the circle centered at 1 with radius 1; （2） If a quantum system S with a time-dependent Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain c-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values F,（t） for all t are always outside of the circle centered at 1 with radius 1-ε. Moreover, some quantitative sufficient conditions for the state of the system at time t to remain ε-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor are established. Lastly, our results are illustrated by a spin-half particle in a rotating magnetic field.展开更多
The design and fabrication of low-cost, high-effidency, and stable oxygen-evolving catalysts are essential for promoting the overall efficiency of water electrolysis. In this study, mesoporous Ni1-xFexOy （0 〈 x 〈 1...The design and fabrication of low-cost, high-effidency, and stable oxygen-evolving catalysts are essential for promoting the overall efficiency of water electrolysis. In this study, mesoporous Ni1-xFexOy （0 〈 x 〈 1, 1 〈y 〈 1.5） nanorods were synthesized by the facile thermal decomposition of Ni-Fe-based coordination polymers. These polymers passed their nanorod-like morphology to oxides, which served as active catalysts for oxygen evolution reaction （OER）. Increasing the Fe-doping amount to 33 at.% decreased the particle size and charge-transfer resistance and increased the surface area, resulting in a reduced overpotential （-302 mV） at 10 mA/cm^2 and a reduced Tafel slope （-42 mV/dec）, which were accompanied by a far improved OER activity compared with those of commercial RuO2 and IrO2 electrocatalysts. At Fe-doping concentrations higher than 33 at.%, the trend of the electrocatalytic parameters started to reverse. The shift in the dopant concentration of Fe was further reflected in the structural transformation from a NiO （〈33 at.% Fe） rock-salt structure to a biphasic NiO/NiFe204 （33 at.% Fe） heterostructure, a NiFe204 （66 at.% Fe） spinel structure, and eventually to α-fe203 （100 at.% Fe）. The efficient water-oxidation activity is ascribed to the highly mesoporous one-dimensional nanostructure, large surface area, and optimal amounts of the dopant Fe. The merits of abundance in the Earth, scalable synthesis, and highly efficient electrocatalytic activity make mesoporous Ni-Fe binary oxides promising oxygen-evolving catalysts for water splitting.展开更多
A successful qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in air-borne particulates in Hong Kong City has been carried out by the heuristic evolving latent projection (HELP) method ...A successful qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in air-borne particulates in Hong Kong City has been carried out by the heuristic evolving latent projection (HELP) method recently developed in chemometrics. The resolution result showed that 47 compounds were involved in this sample. Eighteen of them were interesting PAHs and/or their derivatives. The result agreed very well with the one obtained by capillary column GGMS. The resolved UV-visible spectra match well with the standards. With the help of HELP method, accurate quantitative results were also obtained for all the overlapping peaks. The separation ability of chromatography is greatly enhanced by chemometric methods. The HELP method provides a completely new way for quick and accurate analysis of the two-dimensional data produced by hyphenated chromatographic instruments.展开更多
In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the...In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. Further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.展开更多
Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within ...Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size,providing an excellent opportunity to investigate the genetic basis of body size variation in vertebrates.Herein,we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China Sea.Two genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size,respectively.A total of 180 rapidly evolving genes and two positively selected genes were identified between the two groups.Functional enrichment analyses of these candidate genes revealed distinct enrichment categories between the two groups.These pathways and genes may play important roles in body size variation in groupers through complex regulatory networks.Based on our results,we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection,leading to genetic variations in metabolic patterns,organ development,and lifespan,resulting in body size divergence between the two locally adapted populations.These findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation.展开更多
Personalized recommendation plays a critical role in providing decision-making support for product and service analysis in the field of business intelligence.Recently,deep neural network-based sequential recommendatio...Personalized recommendation plays a critical role in providing decision-making support for product and service analysis in the field of business intelligence.Recently,deep neural network-based sequential recommendation models gained considerable attention.However,existing approaches pay litle attention to users'dynamically evolving interests,which are influenced by product attributes,especially product category.To overcome these challenges,we propose a dynamic personalized recommendation model:DynaPR.Specifically,we first embed product information and attribute information into a unified data space.Then,we exploit long short-term memory(LsTM)networks to characterize sequential behavior over multiple time periods and seize evolving interests by hierarchical LSTM networks.Finally,similarity values between users are measured through pairwise interest features,and personalized recommendation lists are generated.A series of experiments reveal the superiority of the proposed method compared withotheradvanced methods.展开更多
基金Project(20235020) supported by the National Natural Science Foundation of China
文摘The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.
基金We appreciate the financial funding supported by the National Natural Science Foundation of China （No. 51402205）, Natural Science Foundation of Shanxi （No. 2015021058） and Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi （No. STIP-2016131）.
文摘The development of highly efficient and inexpensive catalysts for oxygen evolving reactions （OERs） is extremely urgent for promoting the overall efficiency of water splitting. Herein we report the fabrication of a series of amorphous NiFeB nanoparticles with varying atomic ratios of Fe to （Ni ＋ Fe） （XFe） by a facile chemical-reduction method. The amorphous NiFeB （XFe=0.20） nanoparticles, combining the merits of in situ formation of borate-enriched NiFeOOH catalytic surface layers, intrinsic amorphous nanostructures, and an optimized degree of Fe doping, displayed highly active electrocatalytic performance towards the OER in a broad range of pH values （from alkaline to neutral conditions）. The catalyst exhibited a relatively low overpotential of 216 mV with a Tafel slope of 40 mWdec on Ni foam and 251 mV with a Tafel slope of 43 mV/dec on glassy carbon at 10 mA/cm2 in a 1 M KOH solution, demonstrating much greater OER efficiency than that of commercial RuO2. Long-term stability testing of the OER performance of NiFeB （XFe = 0.20） by chronoamperometry （overpotential （η） = 320 mV） over 200 h revealed no evidence of degradation. Facile, scalable synthesis and highly active water oxidation make the NiFeB nanoparticles very attractive for OER electrocatalysis.
文摘Thoracic Surgery is a continuous evolving specialty. In the past, thoracic surgeons had to make large incisions in order to operate any pathology inside the chest. This often meant big, painful and ugly scars and long recovery times after surgery. But he history of thoracic surgery changed since the begining of video-assisted thoracoscoDic surgery （VATg3
文摘挖掘时态关联规则的目的是为了发现带有时态信息的项集之间有趣的关系.由于数据库经常动态更新,时态关联规则的挖掘也应该适应数据库的更新.然而,现有的大多数算法不仅需要重新挖掘更新的数据库,浪费了大量的时间和效率,而且不能利用已存在的规则定量地预测某些项的变化趋势.本文提出了一个基于多维时态关联规则的演化模糊推理预测建模算法(Evolving fuzzy inference model based on multidimensional temporal association rules,EFI-MTAR),主要优势是构建了一种基于多维时态关联规则的模糊推理建模算法(Fuzzy inference modeling algorithm based on multidimensional temporal association rules,FI-MTAR),实现了对时间序列的定量预测.此外,为了降低规则更新的代价和加快规则预测的速度,提出了概念漂移检测策略来处理时间序列数据以适应数据库的动态更新.实验结果表明了本文提出算法的有效性和准确性.
基金supported by the National Natural Science Foundation of China(Grant No. 11171197)the IFGP of Shaanxi Normal University(Grant No. 2011CXB004)the FRF for the Central Universities(Grant No. GK201002006)
文摘Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values Fn（t） for all t are always on the circle centered at 1 with radius 1; （2） If a quantum system S with a time-dependent Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain c-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values F,（t） for all t are always outside of the circle centered at 1 with radius 1-ε. Moreover, some quantitative sufficient conditions for the state of the system at time t to remain ε-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor are established. Lastly, our results are illustrated by a spin-half particle in a rotating magnetic field.
文摘The design and fabrication of low-cost, high-effidency, and stable oxygen-evolving catalysts are essential for promoting the overall efficiency of water electrolysis. In this study, mesoporous Ni1-xFexOy （0 〈 x 〈 1, 1 〈y 〈 1.5） nanorods were synthesized by the facile thermal decomposition of Ni-Fe-based coordination polymers. These polymers passed their nanorod-like morphology to oxides, which served as active catalysts for oxygen evolution reaction （OER）. Increasing the Fe-doping amount to 33 at.% decreased the particle size and charge-transfer resistance and increased the surface area, resulting in a reduced overpotential （-302 mV） at 10 mA/cm^2 and a reduced Tafel slope （-42 mV/dec）, which were accompanied by a far improved OER activity compared with those of commercial RuO2 and IrO2 electrocatalysts. At Fe-doping concentrations higher than 33 at.%, the trend of the electrocatalytic parameters started to reverse. The shift in the dopant concentration of Fe was further reflected in the structural transformation from a NiO （〈33 at.% Fe） rock-salt structure to a biphasic NiO/NiFe204 （33 at.% Fe） heterostructure, a NiFe204 （66 at.% Fe） spinel structure, and eventually to α-fe203 （100 at.% Fe）. The efficient water-oxidation activity is ascribed to the highly mesoporous one-dimensional nanostructure, large surface area, and optimal amounts of the dopant Fe. The merits of abundance in the Earth, scalable synthesis, and highly efficient electrocatalytic activity make mesoporous Ni-Fe binary oxides promising oxygen-evolving catalysts for water splitting.
文摘A successful qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in air-borne particulates in Hong Kong City has been carried out by the heuristic evolving latent projection (HELP) method recently developed in chemometrics. The resolution result showed that 47 compounds were involved in this sample. Eighteen of them were interesting PAHs and/or their derivatives. The result agreed very well with the one obtained by capillary column GGMS. The resolved UV-visible spectra match well with the standards. With the help of HELP method, accurate quantitative results were also obtained for all the overlapping peaks. The separation ability of chromatography is greatly enhanced by chemometric methods. The HELP method provides a completely new way for quick and accurate analysis of the two-dimensional data produced by hyphenated chromatographic instruments.
基金supported by the National Natural Science Foundation of China (No.12231008 and No.11971185)。
文摘In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. Further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.
基金supported by the National Natural Science Foundation of China (32273136,31872572)Agriculture Research System of China (ARS-47)+1 种基金Science and Technology Planning Project of Guangdong Province (2023B1212060023)Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (SML2023SP201)。
文摘Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size,providing an excellent opportunity to investigate the genetic basis of body size variation in vertebrates.Herein,we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China Sea.Two genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size,respectively.A total of 180 rapidly evolving genes and two positively selected genes were identified between the two groups.Functional enrichment analyses of these candidate genes revealed distinct enrichment categories between the two groups.These pathways and genes may play important roles in body size variation in groupers through complex regulatory networks.Based on our results,we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection,leading to genetic variations in metabolic patterns,organ development,and lifespan,resulting in body size divergence between the two locally adapted populations.These findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation.
文摘Personalized recommendation plays a critical role in providing decision-making support for product and service analysis in the field of business intelligence.Recently,deep neural network-based sequential recommendation models gained considerable attention.However,existing approaches pay litle attention to users'dynamically evolving interests,which are influenced by product attributes,especially product category.To overcome these challenges,we propose a dynamic personalized recommendation model:DynaPR.Specifically,we first embed product information and attribute information into a unified data space.Then,we exploit long short-term memory(LsTM)networks to characterize sequential behavior over multiple time periods and seize evolving interests by hierarchical LSTM networks.Finally,similarity values between users are measured through pairwise interest features,and personalized recommendation lists are generated.A series of experiments reveal the superiority of the proposed method compared withotheradvanced methods.
