Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like cov...Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like covalent organic framework(COF)to form a step-scheme(S-scheme)photocata-lyst for H_(2)O_(2)production.The as-prepared S-scheme photocatalyst exhibits a broad light absorption range with an edge at 810 nm owing to the synergistic effect between the ZnSe QDs and COF.The S-scheme charge-carrier transfer mechanism is validated by performing Fermi level calculations and in-situ X-ray photoelectron and femtosecond transient absorption spectroscopies.Photolumi-nescence,time-resolved photoluminescence,photocurrent response,electrochemical impedance spectroscopy,and electron paramagnetic resonance results show that the S-scheme heterojunction not only promotes charge carrier separation but also boosts the redox ability,resulting in enhanced photocatalytic performance.Remarkably,a 10%-ZnSe QD/COF has excellent photocatalytic H_(2)O_(2)-production activity,and the optimal S-scheme composite with ethanol as the hole scavenger yields a H_(2)O_(2)-production rate of 1895 mol g^(-1)h^(-1).This study presents an example of a high-performance organic/inorganic S-scheme photocatalyst for H_(2)O_(2)production.展开更多
GRAS transcription factors play important roles in plant abiotic stress response,but their characteristics and functions in cotton have not been fully investigated.A cotton SCL4/7 subgroup gene in the GRAS family,GhSC...GRAS transcription factors play important roles in plant abiotic stress response,but their characteristics and functions in cotton have not been fully investigated.A cotton SCL4/7 subgroup gene in the GRAS family,GhSCL4,was found to be induced by NaCl treatments.Nuclear localization and transactivation activity of GhSCL4 indicate its potential role in transcriptional regulation.Transgenic Arabidopsis thaliana over-expressing GhSCL4 showed enhanced resistance to salt and osmotic stress.What’s more,the transcript levels of salt stress-induced genes(AtNHX1 and AtSOS1)and oxidation-related genes(AtAPX3 and AtCSD2)were more highly induced in the GhSCL4 over-expression lines than in wild type after salt treatment.Furthermore,silencing of GhSCL4 resulted in reduced salt tolerance in cotton caused by reactive oxygen species(ROS)enrichment under salt treatment,and antioxidant enzyme activities were accordingly significantly reduced in GhSLC4-silenced lines.These results indicated that GhSCL4 enhances salt tolerance of cotton by detoxifying ROS.In addition,the transient expression assay confirmed an interactive relationship between GhSCL4 and GhCaM7,which indicated that salt tolerance conferred by GhSCL4 might be associated with salt-induced Ca^(2+)/CaM7-mediated signaling.Taken together,GhSCL4 acts as a positive regulator in cotton during salt stress that is potentially useful for engineering salt-tolerant cotton.展开更多
The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected w...The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different intergenomic translocations were identified in 33.3% of individuals; type Ⅰ and Ⅱ translocations were detected with higher frequency. Further analysis revealed that type Ⅰ and Ⅱ translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.展开更多
Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the e...Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the electrochemical properties of lithium–oxygen batteries(LOBs), especially the cycling performance, a high-efficiency cathode catalyst is the most important component.Hence, we aim to demonstrate that CuCr_2O_4@rGO(CCO@rGO) nanocomposites, which are synthesized using a facile hydrothermal method and followed by a series of calcination processes, are an effective cathode catalyst. The obtained CCO@rGO nanocomposites which served as the cathode catalyst of the LOBs exhibited an outstanding cycling performance for over 100 cycles with a fixed capacity of 1000 mAh g^(-1) at a current density of 200 mA g^(-1). The enhanced properties were attributed to the synergistic effect between the high catalytic efficiency of the spinel-structured CCO nanoparticles, the high specific surface area, and high conductivity of the rGO.展开更多
The endophytic fungi in different tissues of Artemisia annua was isolated and purified to explore their ecological distribution and tissue preference, and the extracellular enzyme activities of dominant endophytic fun...The endophytic fungi in different tissues of Artemisia annua was isolated and purified to explore their ecological distribution and tissue preference, and the extracellular enzyme activities of dominant endophytic fungi were determined to characterize the metabolic function of endophytic fungi. The results showed that a total of 67 endophytic fungi were obtained from Artemisia annua tissues. The number and species of endophytic fungi in different tissues were significantly different. The number, colonization rate (CR) and isolation rate (IR) of endophytic fungi in root were significantly higher than those of stem and leaf. The dominant endophytic fungi, diversity and similarity coefficient of endophytic fungi also showed significant difference among tissues. The extracellular enzyme activities of endophytic fungi in different tissues are significantly different. The enzyme activities of endophytic fungi isolated from root are significantly higher than those isolated from stem and leaf. The research results showed that the endophytic fungi in Artemisia annua had significant tissue preference, and the metabolic function of endophytic fungi showed significant difference among tissues. This will lay a foundation for further research, development and utilization of endophytic fungi, and also provide a theoretical basis for screening functional endophytic fungi in Artemisia annua.展开更多
The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ...The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.展开更多
Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanost...Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanostructure with excellent water dispersibility and high drug-loading capacity,a novel nanorattle-structured Fe3O4@SiO2@NaYF4:Yb,Er magnetic upconversion nanorattle(MUCNR)was successfully designed by using Fe3O4 as core and NaYF4:Yb,Er nanocrystals as shell.The microstructures and crystal phase of the as-prepared MUCNRs were evaluated by transmission electron microscopy,Xray powder diffraction and N2 adsorption/desorption isotherms.The Kirkendall effect was adapted to explain the formation mechanism of the MUCNRs.The loading content and encapsulation efficiency of doxorubicin hydrochloride(DOX)could reach as high as 18.2%and 60.7%,respectively.Moreover,the DOX loading MUCNR(DOX-MUCNR)system showed excellent sustained drug release and strong p Hdependent performance,which was conducive to drug release at the slightly acidic microenvironment of tumor.Microcalorimetry was used to quantify the interactions between the carrier structure and drug release rate directly.The heat release rates in the heat-flow diagrams are basically consistent with the DOX release rate,thereby showing that microcalorimetry assay not only provides a unique thermodynamic explanation for the structure–activity relationship of Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs but also provides powerful guidance to avoid the blind selection or design of drug carriers.Therefore,our work firmly provided a comprehensive perspective for using Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs as a remarkable magnetic targeted drug carrier.展开更多
In addition to landscape changes,urbanization also brings about changes in environmental factors that can affect wildlife.Despite the common referral in the published literature to multiple environmental factors such ...In addition to landscape changes,urbanization also brings about changes in environmental factors that can affect wildlife.Despite the common referral in the published literature to multiple environmental factors such as light and noise pollution,there is a gap in knowledge about their combined impact.We developed a multidimensional environmental framework to assess the effect of urbanization and multiple environmental factors(light,noise,and temperature)on life-history traits and breeding success of Barn Swallows(Hirundo rustica)across rural to urban gradients in four locations spanning over 2500 km from North to South China.Over a single breeding season,we measured these environmental factors nearby nests and quantified landscape urbanization over a 1km~2radius.We then analysed the relationships between these multiple environmental factors through a principal component analysis and conducted spatially explicit linear-mixed effects models to assess their effect on lifehistory traits and breeding success.We were particularly interested in understanding whether and how Barn Swallows were able to adapt to such environmental conditions associated with urbanization.The results show that there is significant variation in the exposure to environmental conditions experienced by Barn Swallows breeding across urbanization gradients in China.These changes and their effects are complex due to the behavioural responses ameliorating potential negative effects by selecting nesting sites that minimize exposure to environmental factors.However,significant relationships between landscape urbanization,exposure to environmental factors,and life-history traits such as laying date and clutch size were pervasive.Still,the impact on breeding success was,at least in our sample,negligible,suggesting that Barn Swallows are extremely adaptable to a wide range of environmental features.展开更多
Objective To detect the impact of side branch(SB)lesion length on acute SB occlusion after main vessel(MV)stenting.Methods A total of 516 consecutive patients with 524 bifurcation lesions undergoing one-stent techniqu...Objective To detect the impact of side branch(SB)lesion length on acute SB occlusion after main vessel(MV)stenting.Methods A total of 516 consecutive patients with 524 bifurcation lesions undergoing one-stent techniques were studied.Multivariate logistic regression analysis was performed to identify independent predictors of acute SB occlusion.The lesions were also further divided into two groups according to the median of SB lesion length.The incidence of SB occlusion and lesion characteristics in the two subgroups were compared.展开更多
Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchan...Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchange coupling.Here we propose a general strategy of self-intercalation to achieve enhanced ferromagnetism in bilayer CrI 3.We show that filling either Cr or I atoms into the van der Waals gap of stacked and twisted CrI 3 bilayers can induce the double exchange effect and significantly strengthen the interlayer ferromagnetic coupling.According to our first-principles calculations,the intercalated native atoms act as covalent bridge between two CrI 3 layers and lead to discrepant oxidation states for the Cr atoms.These theoretical results offer a facile route to achieve high-Curie-temperature 2D magnets for device implementation.展开更多
Identifying negation scopes in a text is an important subtask of information extraction, that can benefit other natural language processing tasks, like relation extraction, question answering and sentiment analysis. A...Identifying negation scopes in a text is an important subtask of information extraction, that can benefit other natural language processing tasks, like relation extraction, question answering and sentiment analysis. And serves the task of social media text understanding. The task of negation scope detection can be regarded as a token-level sequence labeling problem. In this paper, we propose different models based on recurrent neural networks (RNNs) and word embedding that can be successfully applied to such tasks without any task-specific feature engineering efforts. Our experimental results show that RNNs, without using any hand-crafted features, outperform feature-rich CRF-based model.展开更多
Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for ...Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants degradation.This Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and growth.Mechanism study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,respectively.The improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation capability.Additionally,a S-scheme charge transfer mechanism including multiple charge transfer channels was proposed.This work could provide an effective strategy for organic pollutants degradation in wastewater.展开更多
To find a greener and more economical approach for treating the Mountain Pass rare earth concentrate(MPREC),a novel "Combination Method",including the processes of oxidizing roasting,HCI leaching and sulfuri...To find a greener and more economical approach for treating the Mountain Pass rare earth concentrate(MPREC),a novel "Combination Method",including the processes of oxidizing roasting,HCI leaching and sulfuric acid roasting,is proposed in this research.In this paper,the effect of phase transition behavior in hydrochloric acid leaching during oxidative roasting at 450-600℃ was studied.During roasting,the bastnasite in MPREC is decomposed into CeLa_(2)O_(3)F_(3) and(Ce_(0.33),La_(0.33),Ca_(0.33))O_(1.5).As the CeLa_(2)O_(3)F_(3) phase has the fluorine-fixation effect,the generated CeLa_(2)O_(3)F_(3) phase can not be dissolved by HCI after roasting at 500 and 550℃,but it can be decomposed by HCI after roasting at over 600℃,resulting in the improvement of the leaching rate of total F element.The maximum leaching efficiency of rare earth elements(REEs) can reach 70.32 wt% at the roasting temperature of 550℃.After roasting at over 600℃,some F^-ions in the solution combined with RE^(3+) to form REF_(3) precipitate and enter the leaching residue,and the others are in the form of [CeF_(3)]^+ in the leaching solution during leaching,therefore,the leaching efficiency of non-ce rium REEs decreases while that of cerium element increases.This work provides basic research for optimizing the actual production process of MPREC.展开更多
Using electrophoretic deposition(EPD)method,the TbF_(3)powders were deposited on the surface of sintered Nd-Fe-B magnets,and the effects of MgCl_(2)on electrophoretic deposition and grain boundary diffusion were inves...Using electrophoretic deposition(EPD)method,the TbF_(3)powders were deposited on the surface of sintered Nd-Fe-B magnets,and the effects of MgCl_(2)on electrophoretic deposition and grain boundary diffusion were investigated.The results show that addition of 5 wt%MgCl_(2)can significantly improve the EPD efficiency and improve the adhesion of the coating by releasing local stress through the formation of special gully morphology.Combining with Biesheuvel equation,the effects of suspension concentration,voltage and time on EPD amount were studied.The Biesheuvel equation can be simplified asγ=AUSct/L,and A(=0.0141-0.0144)in this experiment was calculated to achieve the quantitative calculation of EPD amount.After heat treatment of 875℃×10 h+500℃×1 h,the coercivity of 48H(7 mm)sintered magnet with 0.3 wt%TbF_(3)increases from 18.5 to 22.4 kOe,with an increase of 21.1%.The core-shell structure was observed by a back-scattered scanning electron microscope(BSE-SEM),which proves that the addition of MgCl_(2)has no adverse effect on the grain boundary diffusion of Nd-Fe-B sintered magnets.展开更多
文摘Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like covalent organic framework(COF)to form a step-scheme(S-scheme)photocata-lyst for H_(2)O_(2)production.The as-prepared S-scheme photocatalyst exhibits a broad light absorption range with an edge at 810 nm owing to the synergistic effect between the ZnSe QDs and COF.The S-scheme charge-carrier transfer mechanism is validated by performing Fermi level calculations and in-situ X-ray photoelectron and femtosecond transient absorption spectroscopies.Photolumi-nescence,time-resolved photoluminescence,photocurrent response,electrochemical impedance spectroscopy,and electron paramagnetic resonance results show that the S-scheme heterojunction not only promotes charge carrier separation but also boosts the redox ability,resulting in enhanced photocatalytic performance.Remarkably,a 10%-ZnSe QD/COF has excellent photocatalytic H_(2)O_(2)-production activity,and the optimal S-scheme composite with ethanol as the hole scavenger yields a H_(2)O_(2)-production rate of 1895 mol g^(-1)h^(-1).This study presents an example of a high-performance organic/inorganic S-scheme photocatalyst for H_(2)O_(2)production.
基金supported by funding from the National Natural Science Foundation of China(Grant No.32101683)the Fundamental Research Funds of Zhejiang Sci-Tech University(Grant No.11612932612116).
文摘GRAS transcription factors play important roles in plant abiotic stress response,but their characteristics and functions in cotton have not been fully investigated.A cotton SCL4/7 subgroup gene in the GRAS family,GhSCL4,was found to be induced by NaCl treatments.Nuclear localization and transactivation activity of GhSCL4 indicate its potential role in transcriptional regulation.Transgenic Arabidopsis thaliana over-expressing GhSCL4 showed enhanced resistance to salt and osmotic stress.What’s more,the transcript levels of salt stress-induced genes(AtNHX1 and AtSOS1)and oxidation-related genes(AtAPX3 and AtCSD2)were more highly induced in the GhSCL4 over-expression lines than in wild type after salt treatment.Furthermore,silencing of GhSCL4 resulted in reduced salt tolerance in cotton caused by reactive oxygen species(ROS)enrichment under salt treatment,and antioxidant enzyme activities were accordingly significantly reduced in GhSLC4-silenced lines.These results indicated that GhSCL4 enhances salt tolerance of cotton by detoxifying ROS.In addition,the transient expression assay confirmed an interactive relationship between GhSCL4 and GhCaM7,which indicated that salt tolerance conferred by GhSCL4 might be associated with salt-induced Ca^(2+)/CaM7-mediated signaling.Taken together,GhSCL4 acts as a positive regulator in cotton during salt stress that is potentially useful for engineering salt-tolerant cotton.
基金supported by the National Natural Science Foundation of Qinghai Province (2015-ZJ-903)the National Natural Science Foundation of China (31072075)
文摘The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different intergenomic translocations were identified in 33.3% of individuals; type Ⅰ and Ⅱ translocations were detected with higher frequency. Further analysis revealed that type Ⅰ and Ⅱ translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.
基金jointly supported by National Science Foundation of China (Grant Numbers: 11572271 and 51302236)the Principal Fund of Xiamen University (Hosted by Guanghui Yue, 2018)
文摘Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the electrochemical properties of lithium–oxygen batteries(LOBs), especially the cycling performance, a high-efficiency cathode catalyst is the most important component.Hence, we aim to demonstrate that CuCr_2O_4@rGO(CCO@rGO) nanocomposites, which are synthesized using a facile hydrothermal method and followed by a series of calcination processes, are an effective cathode catalyst. The obtained CCO@rGO nanocomposites which served as the cathode catalyst of the LOBs exhibited an outstanding cycling performance for over 100 cycles with a fixed capacity of 1000 mAh g^(-1) at a current density of 200 mA g^(-1). The enhanced properties were attributed to the synergistic effect between the high catalytic efficiency of the spinel-structured CCO nanoparticles, the high specific surface area, and high conductivity of the rGO.
文摘The endophytic fungi in different tissues of Artemisia annua was isolated and purified to explore their ecological distribution and tissue preference, and the extracellular enzyme activities of dominant endophytic fungi were determined to characterize the metabolic function of endophytic fungi. The results showed that a total of 67 endophytic fungi were obtained from Artemisia annua tissues. The number and species of endophytic fungi in different tissues were significantly different. The number, colonization rate (CR) and isolation rate (IR) of endophytic fungi in root were significantly higher than those of stem and leaf. The dominant endophytic fungi, diversity and similarity coefficient of endophytic fungi also showed significant difference among tissues. The extracellular enzyme activities of endophytic fungi in different tissues are significantly different. The enzyme activities of endophytic fungi isolated from root are significantly higher than those isolated from stem and leaf. The research results showed that the endophytic fungi in Artemisia annua had significant tissue preference, and the metabolic function of endophytic fungi showed significant difference among tissues. This will lay a foundation for further research, development and utilization of endophytic fungi, and also provide a theoretical basis for screening functional endophytic fungi in Artemisia annua.
基金funded by SHAN SHUI Conservation Centre,Beijing。
文摘The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.
基金supported by the Key Research and Development Plan of Shaanxi Province(2020GY-313)the Specialized Research Fund of Education Department of Shaanxi Province(19JK0255)+1 种基金the Specialized Scientific Research Fund Projects of Academician Shengyong Zhang(18YSZX001)the Science and Technology Innovation Team of Shangluo University(20SCX02)。
文摘Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanostructure with excellent water dispersibility and high drug-loading capacity,a novel nanorattle-structured Fe3O4@SiO2@NaYF4:Yb,Er magnetic upconversion nanorattle(MUCNR)was successfully designed by using Fe3O4 as core and NaYF4:Yb,Er nanocrystals as shell.The microstructures and crystal phase of the as-prepared MUCNRs were evaluated by transmission electron microscopy,Xray powder diffraction and N2 adsorption/desorption isotherms.The Kirkendall effect was adapted to explain the formation mechanism of the MUCNRs.The loading content and encapsulation efficiency of doxorubicin hydrochloride(DOX)could reach as high as 18.2%and 60.7%,respectively.Moreover,the DOX loading MUCNR(DOX-MUCNR)system showed excellent sustained drug release and strong p Hdependent performance,which was conducive to drug release at the slightly acidic microenvironment of tumor.Microcalorimetry was used to quantify the interactions between the carrier structure and drug release rate directly.The heat release rates in the heat-flow diagrams are basically consistent with the DOX release rate,thereby showing that microcalorimetry assay not only provides a unique thermodynamic explanation for the structure–activity relationship of Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs but also provides powerful guidance to avoid the blind selection or design of drug carriers.Therefore,our work firmly provided a comprehensive perspective for using Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs as a remarkable magnetic targeted drug carrier.
基金funded by the National Natural Science Foundation of China(31770454 to E.P.N.,X.X.and R.J.S.)。
文摘In addition to landscape changes,urbanization also brings about changes in environmental factors that can affect wildlife.Despite the common referral in the published literature to multiple environmental factors such as light and noise pollution,there is a gap in knowledge about their combined impact.We developed a multidimensional environmental framework to assess the effect of urbanization and multiple environmental factors(light,noise,and temperature)on life-history traits and breeding success of Barn Swallows(Hirundo rustica)across rural to urban gradients in four locations spanning over 2500 km from North to South China.Over a single breeding season,we measured these environmental factors nearby nests and quantified landscape urbanization over a 1km~2radius.We then analysed the relationships between these multiple environmental factors through a principal component analysis and conducted spatially explicit linear-mixed effects models to assess their effect on lifehistory traits and breeding success.We were particularly interested in understanding whether and how Barn Swallows were able to adapt to such environmental conditions associated with urbanization.The results show that there is significant variation in the exposure to environmental conditions experienced by Barn Swallows breeding across urbanization gradients in China.These changes and their effects are complex due to the behavioural responses ameliorating potential negative effects by selecting nesting sites that minimize exposure to environmental factors.However,significant relationships between landscape urbanization,exposure to environmental factors,and life-history traits such as laying date and clutch size were pervasive.Still,the impact on breeding success was,at least in our sample,negligible,suggesting that Barn Swallows are extremely adaptable to a wide range of environmental features.
文摘Objective To detect the impact of side branch(SB)lesion length on acute SB occlusion after main vessel(MV)stenting.Methods A total of 516 consecutive patients with 524 bifurcation lesions undergoing one-stent techniques were studied.Multivariate logistic regression analysis was performed to identify independent predictors of acute SB occlusion.The lesions were also further divided into two groups according to the median of SB lesion length.The incidence of SB occlusion and lesion characteristics in the two subgroups were compared.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11974068 and 11874097)the China Postdoctoral Science Foundation(Grant Nos.BX20190052 and 2020M670739)the Fundamental Research Funds for the Central Universities of China(Grant Nos.DUT20LAB110 and DUT19LK12)
文摘Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchange coupling.Here we propose a general strategy of self-intercalation to achieve enhanced ferromagnetism in bilayer CrI 3.We show that filling either Cr or I atoms into the van der Waals gap of stacked and twisted CrI 3 bilayers can induce the double exchange effect and significantly strengthen the interlayer ferromagnetic coupling.According to our first-principles calculations,the intercalated native atoms act as covalent bridge between two CrI 3 layers and lead to discrepant oxidation states for the Cr atoms.These theoretical results offer a facile route to achieve high-Curie-temperature 2D magnets for device implementation.
文摘Identifying negation scopes in a text is an important subtask of information extraction, that can benefit other natural language processing tasks, like relation extraction, question answering and sentiment analysis. And serves the task of social media text understanding. The task of negation scope detection can be regarded as a token-level sequence labeling problem. In this paper, we propose different models based on recurrent neural networks (RNNs) and word embedding that can be successfully applied to such tasks without any task-specific feature engineering efforts. Our experimental results show that RNNs, without using any hand-crafted features, outperform feature-rich CRF-based model.
基金supported by the Specialized Research Fund of Education Department of Shaanxi Province(No.22JY015)the College Students Innovation and Entrepreneurship Plan Training Program(No.S202211396006).
文摘Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants degradation.This Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and growth.Mechanism study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,respectively.The improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation capability.Additionally,a S-scheme charge transfer mechanism including multiple charge transfer channels was proposed.This work could provide an effective strategy for organic pollutants degradation in wastewater.
基金Project supported by the National Key Research and Development Program of China(2020YFC1909104)。
文摘To find a greener and more economical approach for treating the Mountain Pass rare earth concentrate(MPREC),a novel "Combination Method",including the processes of oxidizing roasting,HCI leaching and sulfuric acid roasting,is proposed in this research.In this paper,the effect of phase transition behavior in hydrochloric acid leaching during oxidative roasting at 450-600℃ was studied.During roasting,the bastnasite in MPREC is decomposed into CeLa_(2)O_(3)F_(3) and(Ce_(0.33),La_(0.33),Ca_(0.33))O_(1.5).As the CeLa_(2)O_(3)F_(3) phase has the fluorine-fixation effect,the generated CeLa_(2)O_(3)F_(3) phase can not be dissolved by HCI after roasting at 500 and 550℃,but it can be decomposed by HCI after roasting at over 600℃,resulting in the improvement of the leaching rate of total F element.The maximum leaching efficiency of rare earth elements(REEs) can reach 70.32 wt% at the roasting temperature of 550℃.After roasting at over 600℃,some F^-ions in the solution combined with RE^(3+) to form REF_(3) precipitate and enter the leaching residue,and the others are in the form of [CeF_(3)]^+ in the leaching solution during leaching,therefore,the leaching efficiency of non-ce rium REEs decreases while that of cerium element increases.This work provides basic research for optimizing the actual production process of MPREC.
基金supported by the National Key R&D Program of China(2020YFC2008100)the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2017-12M-3002)+2 种基金the Zhejiang Province Science and Technology Department Key R&D Program(2021C03097 and 2022C03063)the Binjiang Institute of Zhejiang University(ZY202205SMKY001)the Natural Science Foundation of Zhejiang Province(LQ22H020008)。
基金supported by the National Key Research and Development Program of China(2021YFB3500201,2021YFB3500202)the Beijing Youth Top-Notch Team Support Project of China(2018000021223TD10)+2 种基金the Beijing NOVA Program(Z211100002121092)the Natural Science Foundation of Hebei Province(E2021103006)the Hebei Province International Science and Technology Cooperation Base Construction Project of China(20591002D)。
文摘Using electrophoretic deposition(EPD)method,the TbF_(3)powders were deposited on the surface of sintered Nd-Fe-B magnets,and the effects of MgCl_(2)on electrophoretic deposition and grain boundary diffusion were investigated.The results show that addition of 5 wt%MgCl_(2)can significantly improve the EPD efficiency and improve the adhesion of the coating by releasing local stress through the formation of special gully morphology.Combining with Biesheuvel equation,the effects of suspension concentration,voltage and time on EPD amount were studied.The Biesheuvel equation can be simplified asγ=AUSct/L,and A(=0.0141-0.0144)in this experiment was calculated to achieve the quantitative calculation of EPD amount.After heat treatment of 875℃×10 h+500℃×1 h,the coercivity of 48H(7 mm)sintered magnet with 0.3 wt%TbF_(3)increases from 18.5 to 22.4 kOe,with an increase of 21.1%.The core-shell structure was observed by a back-scattered scanning electron microscope(BSE-SEM),which proves that the addition of MgCl_(2)has no adverse effect on the grain boundary diffusion of Nd-Fe-B sintered magnets.
