目前大多数方面级情感分类研究都忽略了方面词的建模,以及方面词与上下文之间的交互信息,并且难以体现语法上与方面词有直接联系上下文单词的重要程度。针对上述问题,提出基于方面词交互(aspect word interaction,AWI)和图卷积网络(grap...目前大多数方面级情感分类研究都忽略了方面词的建模,以及方面词与上下文之间的交互信息,并且难以体现语法上与方面词有直接联系上下文单词的重要程度。针对上述问题,提出基于方面词交互(aspect word interaction,AWI)和图卷积网络(graph convolutional network,GCN)的方面级情感分类模型(AWI-GCN)。使用双向长短期记忆网络(bi-directional long short-term memory,Bi-LSTM)分别提取方面词和上下文的特征;采用GCN根据句法依存树进一步提取与方面词有直接语法联系的上下文情感特征;利用注意力机制学习方面词与上下文的交互信息,同时提取上下文中为方面词情感分类做出重要贡献的情感特征。针对3个公开数据集上的仿真实验结果表明,AWI-GCN模型相比当前代表模型取得了更好的情感分类效果。展开更多
The second edition of the expert consensus on pediatric nutrition was formed based on a global update of pedia-tric nutrition guidelines or consensus worldwide,the management of congenital heart disease,and the result...The second edition of the expert consensus on pediatric nutrition was formed based on a global update of pedia-tric nutrition guidelines or consensus worldwide,the management of congenital heart disease,and the results of multi-center clinical nutrition research for congenital heart disease following thefirst Chinese consensus edition of 2016.The consensus was also shaped by the results of three discussion sessions and two questionnaires con-ducted by the 13-member collaboration group.This process was informed by both clinical guidelines and expert consensus.The quality of literature,both in English and Chinese,and the level of recommendations were evaluated using the Grading of Recommendations Assessment,Development,and Evaluations(GRADE)system.展开更多
The upper-ocean responses to Typhoon Megi (2010) are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model (POM) to assess th...The upper-ocean responses to Typhoon Megi (2010) are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model (POM) to assess the storm, which affected the Northwest Pacific Ocean (NWP) and the South China Sea (SCS). Results show that the upwelling and entrainment experiment together account for 93% of the SST anomalies, where typhoon-induced upwelling may cause strong ocean cooling. In addition, the anomalous SST cooling is stronger in the SCS than in the NWP. The most striking feature of the ocean response is the presence of a two-layer inertial wave in the SCS--a feature that is absent in the NWE The near-inertial oscillations can be generated as typhoon wakes, which have maximum flow velocity in the surface mixed layer and may last for a few days, after the typhoon's passage. Along the typhoon tracks, the horizontal currents in the upper ocean show a series of alternating negative and positive anomalies emanating from the typhoon.展开更多
Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)...Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)-benzene- 1,3-diol and (-)-5-(1,2- dihydroxypentyl)benzene- 1,3-diol.展开更多
(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramic...(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramics were investigated.The phase structures of the ceramics transform from orthorhombic to pseudocubic phases and the grain sizes decrease gradually with BMZ content(x) increasing.Additionally,BMZ additions can significantly enhance the dielectric temperature stability and decrease the dielectric loss of ceramics over a relatively broad temperature range.KNLNC-0.02 BMZ ceramics exhibit high dielectric permittivity(εr=1542) and small variation(Δεr/ε(r150℃)≤±15%)in dielectric permittivity from 100 to 375℃,and low dielectric loss(tanδ≤2%) in the temperature range of 100-350℃,which suggests that this ceramic is a candidate for high-temperature capacitor application.展开更多
[Objectives]To observe the protective effect of Cordyceps cicadae polysaccharides on acute liver injury induced by D-galactosamine( D-GlaN) in mice,and to explore its mechanism. [Methods] Seventy-five male Kunming mic...[Objectives]To observe the protective effect of Cordyceps cicadae polysaccharides on acute liver injury induced by D-galactosamine( D-GlaN) in mice,and to explore its mechanism. [Methods] Seventy-five male Kunming mice were randomly and evenly divided into 5 groups according to the digital table method: normal group( CK)( injected intraperitoneally with saline solution),model group( injected intraperitoneally with D-GlaN),low-dose C. cicadae polysaccharides group( administered with 0. 5 g/kg of C. cicadae polysaccharides solution by gavage),middle-dose C. cicadae polysaccharides group( administered with 1. 0 g/kg of C. cicadae polysaccharides solution by gavage) and high-dose C. cicadae polysaccharides group( administered with 2. 0 g/kg of C. cicadae polysaccharides solution by gavage). After 12 d of administration,the liver histopathological score,liver homogenate indexes( superoxide dismutase,SOD; malondialdehyde,MDA; glutathione peroxidase,GSH-Px; nitric oxide,NO) and serum markers( aspartate transaminase,AST; alanine transaminase,ALT; alkaline phosphatase,ALP; cholinesterase,CHE) of mice in each group were detected. The expression levels of nuclear factor-κB( NF-κB) and tumor necrosis factor-α( TNF-α) in liver tissues were detected by immunohistochemistry. [Results]The liver histopathological score and the MDA,NO,AST,ALT,ALP,NF-κB and TNF-α levels were significantly higher( P < 0. 05) and the SOD,GSH-Px and CHE levels were significantly lower( P <0. 05) in the model group compared with the normal group. Compared with those in the model group,the liver tissue histopathological scores in the low-,middle-and high-dose C. cicadae polysaccharides groups were all significantly reduced( P < 0. 05). With the increase of treatment dose,the liver tissue histopathological scores showed a significant decrease( P < 0. 05). Compared with the model group,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α were significantly lower( P < 0. 05),and the levels of SOD,GSH-Px and CHE were significantly higher( P < 0. 05) in the low-,middle-and high-dose C. cicadae polysaccharides groups. With the increase of treatment dose,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α declined significantly( P < 0. 05),while the levels of SOD,GSH-Px and CHE rose significantly( P < 0. 05). [Conclusions] C. cicadae polysaccharides have a significant protective effect on D-GlaN-induced acute liver injury in mice in a dose-dependent manner,and the mechanism may be related to the inhibition of NF-κB inflammatory signaling pathway.展开更多
In current study, cancer stem-like cells in the murine melanoma B16F10 cells were investigated. CD phenotypes of the B16F10 cells were analyzed by flow cytometry, and the specific CD phenotype cells from the B16F10 ce...In current study, cancer stem-like cells in the murine melanoma B16F10 cells were investigated. CD phenotypes of the B16F10 cells were analyzed by flow cytometry, and the specific CD phenotype cells from the B16F10 cells were isolated by MACS. Then we used colony formation assay in soft agar media, the cell growth assay in serum-free culture media as well as the tumorigenicity investigation of the specific CD phenotype cells in C57BL/6 mice, respectively, to identify cancer stem-like cells in the B16F10 cells. The results showed that the B16F10 cells could form spherical clones in serum-free culture media, and the rate of clonegenesis of CD133^+, CD44^+ and CD44^+CD133^+ cells was higher than that of CD133^-, CD44^- and CD44^+CD133^+ cells in soft agar media, respectively. The tumorigenic potential of CD133^+, CD44^+, CD44^+CD133^+ cells and CD44^+CD133^+CD24^+ cells was stronger than that of CD133^-, CD44^-, CD44^+CD133^- cells and CD44^+CD133^+CD24^- cells in mice, respectively. In conclusion, the CD44^+CD133^+CD24^+ cells have some biological properties of cancer stem-like cells or are highly similar to the characteristics of cancer stem cells (CSC). These results provide an important method for identifying cancer stem-like cells in B16F10 cells and for further cancer target therapy. Cellular & Molecular Immunology.展开更多
The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind ...The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.展开更多
We investigate the effects of high pressure and physical aging on the boson peak and thermal expansion of a typical metallic glass. Specifically, the thermal expansion coefficient and boson peak intensity monotonicall...We investigate the effects of high pressure and physical aging on the boson peak and thermal expansion of a typical metallic glass. Specifically, the thermal expansion coefficient and boson peak intensity monotonically decrease during physical aging.With the increase of high pressure, the boson peak intensity and the thermal expansion coefficient coincidently experience an incipient decrease and then a subsequent increase. The boson peak intensity shows an approximately linear relationship with the thermal expansion coefficient. The thermal expansion can be affected by structural relaxation or rejuvenation, which can reflect the flow units variation and atomic packing of a metallic glass. Our results indicate a direct link between structural relaxation or rejuvenation and fast boson peak dynamics, providing insights into the boson peak behavior and structural heterogeneity of metallic glasses.展开更多
Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/...Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/TiO_(2) SMP)were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation.The microstructure and properties of the Ti^(3+)/TiO_(2) SMP were characterized by X-ray diffraction(XRD),UVevisible diffuse reflection(UVeVis DRS),scanning electron microscopy(SEM),electron paramagnetic resonance(EPR),solid-state photoluminescence spectroscopy(PLS)and X-ray photoelectron spectroscopy(XPS).The Ti^(3+)/TiO_(2) SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product.Effects of solvent,reaction temperature,reaction time and oxygen pressure on the formation of cyclohexanone were investigated.The cyclohexane oxidation over the Ti^(3+)/TiO_(2) SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane(i.e.,95.1%).Based on the controlled experimental results with different radical scavengers,the hole(h^(+))is critical for the activation of cyclohexane.展开更多
Inspired by the intricate eukaryotic cell structure,the spontaneously assembling multicompartments capable of spatiotemporally regulated biomacromolecules transportation is still a challenge.Here,a heterogeneous prote...Inspired by the intricate eukaryotic cell structure,the spontaneously assembling multicompartments capable of spatiotemporally regulated biomacromolecules transportation is still a challenge.Here,a heterogeneous proteinosome-based multicompartment was designed and constructed by combining aqueous two-phase system and Pickering emulsion methods.By loading PEGylated insulin with boronic acid group into the multicompartment and glucose oxidase(GOx)into the innermost microgel domain,a short-or long-term transportation pathway of the loaded insulin was constructed by responding to the concentration of glucose.Moreover,the diminution of dynamic boronic ester bonding,the hindrance of polyethylene oxide micro-chamber,electrostatic interaction and the swelling behavior of hydrogel triggered by GOx/glucose reaction resulted in spatiotemporally controlled multi-pathway transportation mode with the releasing of insulin loaded inside the innermost microgel at high concentration of glucose(10 mg·mL^(-1)).Specially,by incorporating rhodamine B and fluorescein labelled BSA into the multicompartment,the release procedure of the loaded insulin can be monitored by the fluorescence color-change.Overall,a multimode microcompartment is constructed which is then expected to provide a promising platform for further therapeutic protein,gene and drug delivery,as well as towards the design of complicated cell biomimetics.展开更多
Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether este...Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been investigated.The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical modeling.Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption.Compared to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain structure.Furthermore,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction process.Based on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and robustly.Among them,COF and WV can be best predicted with an R^(2) of about 0.90.展开更多
文摘目前大多数方面级情感分类研究都忽略了方面词的建模,以及方面词与上下文之间的交互信息,并且难以体现语法上与方面词有直接联系上下文单词的重要程度。针对上述问题,提出基于方面词交互(aspect word interaction,AWI)和图卷积网络(graph convolutional network,GCN)的方面级情感分类模型(AWI-GCN)。使用双向长短期记忆网络(bi-directional long short-term memory,Bi-LSTM)分别提取方面词和上下文的特征;采用GCN根据句法依存树进一步提取与方面词有直接语法联系的上下文情感特征;利用注意力机制学习方面词与上下文的交互信息,同时提取上下文中为方面词情感分类做出重要贡献的情感特征。针对3个公开数据集上的仿真实验结果表明,AWI-GCN模型相比当前代表模型取得了更好的情感分类效果。
基金supported by the National Natural Science Foundation of China(81970265,82270310)a Sub-Project of the National Key R&D Program“The recognition and Identification of Genetic Pathogenic Genes for Structural Birth Defects”(2021YFC2701002)+1 种基金Nanjing Science and Technology Development Project(2019060007)Jiangsu Provincial Key Research and Development Program(BE2023662).
文摘The second edition of the expert consensus on pediatric nutrition was formed based on a global update of pedia-tric nutrition guidelines or consensus worldwide,the management of congenital heart disease,and the results of multi-center clinical nutrition research for congenital heart disease following thefirst Chinese consensus edition of 2016.The consensus was also shaped by the results of three discussion sessions and two questionnaires con-ducted by the 13-member collaboration group.This process was informed by both clinical guidelines and expert consensus.The quality of literature,both in English and Chinese,and the level of recommendations were evaluated using the Grading of Recommendations Assessment,Development,and Evaluations(GRADE)system.
基金supported by the National Key Basic Research and Development Plan(Grant No.2015CB953900)the National Natural Science Foundation of China(Grant No.41176005)+1 种基金the Public Science and Technology Research Funds Projects of the Ocean(Grant No.GYHY201105018)the China R&D Special Fund for Public Welfare Industry(GYHY 201306016)
文摘The upper-ocean responses to Typhoon Megi (2010) are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model (POM) to assess the storm, which affected the Northwest Pacific Ocean (NWP) and the South China Sea (SCS). Results show that the upwelling and entrainment experiment together account for 93% of the SST anomalies, where typhoon-induced upwelling may cause strong ocean cooling. In addition, the anomalous SST cooling is stronger in the SCS than in the NWP. The most striking feature of the ocean response is the presence of a two-layer inertial wave in the SCS--a feature that is absent in the NWE The near-inertial oscillations can be generated as typhoon wakes, which have maximum flow velocity in the surface mixed layer and may last for a few days, after the typhoon's passage. Along the typhoon tracks, the horizontal currents in the upper ocean show a series of alternating negative and positive anomalies emanating from the typhoon.
文摘Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)-benzene- 1,3-diol and (-)-5-(1,2- dihydroxypentyl)benzene- 1,3-diol.
基金financially supported by the National Natural Science Foundation of China(No.21501007)the Industrial Science and Technology Plan in Shaanxi Province of China (No.2016GY-226)+1 种基金the Doctoral Scientific Research Starting Foundation of Baoji University of Arts and Sciences (No.ZK15044)the Undergraduate Training Programs for Innovation and Entrepreneurship (No.201610721039)
文摘(1-x)(K(0.495)Na(0.495)La(0.01))(Nb(0.997)Cu(0.0075))O3-xBi(Mg(0.5)Zr(0.5))O3(abbreviated as KNLNC-xBMZ) ceramics were designed and prepared.The phase transition,microstructure and electrical properties of the ceramics were investigated.The phase structures of the ceramics transform from orthorhombic to pseudocubic phases and the grain sizes decrease gradually with BMZ content(x) increasing.Additionally,BMZ additions can significantly enhance the dielectric temperature stability and decrease the dielectric loss of ceramics over a relatively broad temperature range.KNLNC-0.02 BMZ ceramics exhibit high dielectric permittivity(εr=1542) and small variation(Δεr/ε(r150℃)≤±15%)in dielectric permittivity from 100 to 375℃,and low dielectric loss(tanδ≤2%) in the temperature range of 100-350℃,which suggests that this ceramic is a candidate for high-temperature capacitor application.
基金Supported by Research Project for Practice Development of National TCM Clinical Research Bases(JDZX2012059)
文摘[Objectives]To observe the protective effect of Cordyceps cicadae polysaccharides on acute liver injury induced by D-galactosamine( D-GlaN) in mice,and to explore its mechanism. [Methods] Seventy-five male Kunming mice were randomly and evenly divided into 5 groups according to the digital table method: normal group( CK)( injected intraperitoneally with saline solution),model group( injected intraperitoneally with D-GlaN),low-dose C. cicadae polysaccharides group( administered with 0. 5 g/kg of C. cicadae polysaccharides solution by gavage),middle-dose C. cicadae polysaccharides group( administered with 1. 0 g/kg of C. cicadae polysaccharides solution by gavage) and high-dose C. cicadae polysaccharides group( administered with 2. 0 g/kg of C. cicadae polysaccharides solution by gavage). After 12 d of administration,the liver histopathological score,liver homogenate indexes( superoxide dismutase,SOD; malondialdehyde,MDA; glutathione peroxidase,GSH-Px; nitric oxide,NO) and serum markers( aspartate transaminase,AST; alanine transaminase,ALT; alkaline phosphatase,ALP; cholinesterase,CHE) of mice in each group were detected. The expression levels of nuclear factor-κB( NF-κB) and tumor necrosis factor-α( TNF-α) in liver tissues were detected by immunohistochemistry. [Results]The liver histopathological score and the MDA,NO,AST,ALT,ALP,NF-κB and TNF-α levels were significantly higher( P < 0. 05) and the SOD,GSH-Px and CHE levels were significantly lower( P <0. 05) in the model group compared with the normal group. Compared with those in the model group,the liver tissue histopathological scores in the low-,middle-and high-dose C. cicadae polysaccharides groups were all significantly reduced( P < 0. 05). With the increase of treatment dose,the liver tissue histopathological scores showed a significant decrease( P < 0. 05). Compared with the model group,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α were significantly lower( P < 0. 05),and the levels of SOD,GSH-Px and CHE were significantly higher( P < 0. 05) in the low-,middle-and high-dose C. cicadae polysaccharides groups. With the increase of treatment dose,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α declined significantly( P < 0. 05),while the levels of SOD,GSH-Px and CHE rose significantly( P < 0. 05). [Conclusions] C. cicadae polysaccharides have a significant protective effect on D-GlaN-induced acute liver injury in mice in a dose-dependent manner,and the mechanism may be related to the inhibition of NF-κB inflammatory signaling pathway.
基金supported in part by National Natural Science Foundation of China(No.90406023)Science Foundation of Southeast University(No.9223001446)Science Foundation of Jiangsu Province Hygienical Division,China(No.16230005777).
文摘In current study, cancer stem-like cells in the murine melanoma B16F10 cells were investigated. CD phenotypes of the B16F10 cells were analyzed by flow cytometry, and the specific CD phenotype cells from the B16F10 cells were isolated by MACS. Then we used colony formation assay in soft agar media, the cell growth assay in serum-free culture media as well as the tumorigenicity investigation of the specific CD phenotype cells in C57BL/6 mice, respectively, to identify cancer stem-like cells in the B16F10 cells. The results showed that the B16F10 cells could form spherical clones in serum-free culture media, and the rate of clonegenesis of CD133^+, CD44^+ and CD44^+CD133^+ cells was higher than that of CD133^-, CD44^- and CD44^+CD133^+ cells in soft agar media, respectively. The tumorigenic potential of CD133^+, CD44^+, CD44^+CD133^+ cells and CD44^+CD133^+CD24^+ cells was stronger than that of CD133^-, CD44^-, CD44^+CD133^- cells and CD44^+CD133^+CD24^- cells in mice, respectively. In conclusion, the CD44^+CD133^+CD24^+ cells have some biological properties of cancer stem-like cells or are highly similar to the characteristics of cancer stem cells (CSC). These results provide an important method for identifying cancer stem-like cells in B16F10 cells and for further cancer target therapy. Cellular & Molecular Immunology.
基金National Natural Science Fund(51675006)the project of Science and Technology Department of Shaanxi Province(2016JZ017)the Local Servicing Research Project of the Education Department of Shanxi Province(15JF007).
文摘The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.
基金supported by the National Natural Science Foundation of China(Grant Nos.51801083,11790291,51461165101,51801124,and51671211)the Natural Science Foundation of Jiangsu Province(Grant No.BK20181044)。
文摘We investigate the effects of high pressure and physical aging on the boson peak and thermal expansion of a typical metallic glass. Specifically, the thermal expansion coefficient and boson peak intensity monotonically decrease during physical aging.With the increase of high pressure, the boson peak intensity and the thermal expansion coefficient coincidently experience an incipient decrease and then a subsequent increase. The boson peak intensity shows an approximately linear relationship with the thermal expansion coefficient. The thermal expansion can be affected by structural relaxation or rejuvenation, which can reflect the flow units variation and atomic packing of a metallic glass. Our results indicate a direct link between structural relaxation or rejuvenation and fast boson peak dynamics, providing insights into the boson peak behavior and structural heterogeneity of metallic glasses.
基金the support of this work by National Key Research and Development Plan(Grant No.2016YFC0303704)the National Natural Science Foundation of China(Grant No.21676296).
文摘Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/TiO_(2) SMP)were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation.The microstructure and properties of the Ti^(3+)/TiO_(2) SMP were characterized by X-ray diffraction(XRD),UVevisible diffuse reflection(UVeVis DRS),scanning electron microscopy(SEM),electron paramagnetic resonance(EPR),solid-state photoluminescence spectroscopy(PLS)and X-ray photoelectron spectroscopy(XPS).The Ti^(3+)/TiO_(2) SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product.Effects of solvent,reaction temperature,reaction time and oxygen pressure on the formation of cyclohexanone were investigated.The cyclohexane oxidation over the Ti^(3+)/TiO_(2) SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane(i.e.,95.1%).Based on the controlled experimental results with different radical scavengers,the hole(h^(+))is critical for the activation of cyclohexane.
基金We thank NSFC(Nos.51873050 and 21871069)for financial support.
文摘Inspired by the intricate eukaryotic cell structure,the spontaneously assembling multicompartments capable of spatiotemporally regulated biomacromolecules transportation is still a challenge.Here,a heterogeneous proteinosome-based multicompartment was designed and constructed by combining aqueous two-phase system and Pickering emulsion methods.By loading PEGylated insulin with boronic acid group into the multicompartment and glucose oxidase(GOx)into the innermost microgel domain,a short-or long-term transportation pathway of the loaded insulin was constructed by responding to the concentration of glucose.Moreover,the diminution of dynamic boronic ester bonding,the hindrance of polyethylene oxide micro-chamber,electrostatic interaction and the swelling behavior of hydrogel triggered by GOx/glucose reaction resulted in spatiotemporally controlled multi-pathway transportation mode with the releasing of insulin loaded inside the innermost microgel at high concentration of glucose(10 mg·mL^(-1)).Specially,by incorporating rhodamine B and fluorescein labelled BSA into the multicompartment,the release procedure of the loaded insulin can be monitored by the fluorescence color-change.Overall,a multimode microcompartment is constructed which is then expected to provide a promising platform for further therapeutic protein,gene and drug delivery,as well as towards the design of complicated cell biomimetics.
基金the National Natural Science Foundation of China(No.52175156)the Key Research and Development Projects of Shaanxi Province(No.2021GY-157)+1 种基金the Young Talent fund of University Association for Science and Technology in Shaanxi(No.20220615)the Special Fund for Basic Scientific Research of Central Colleges(Chang an University)with Nos.300102221512,300102221510,and 300102222502.
文摘Development of energy-efficient lubricants is a way to reduce energy consumption for transportation,with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils.Oligoether esters(OEEs),as a low-viscosity ester base oil,have characteristics such as simple synthesis and excellent lubrication effect;however,the application of OEEs in tribology field has rarely been investigated.The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure‒property relationship(QSPR)through a combination of experiment and statistical modeling.Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption.Compared to branched-chain OEEs,straight-chain OEEs exhibited reduced wear,which was mainly due to the thicker adsorption film formed by the straight-chain structure.Furthermore,carbon films were detected on lightly worn surfaces,indicating that OEEs underwent oxidation during the friction process.Based on the results of principal component analysis(PCA)and partial least squares(PLS),it could be found that the predictive models of viscosity‒temperature performance,thermal stability performance,coefficient of friction(COF),and wear volume(WV)performed well and robustly.Among them,COF and WV can be best predicted with an R^(2) of about 0.90.