Accurate short-term wind power forecast technique plays a crucial role in maintaining the safety and economic efficiency of smart grids.Although numerous studies have employed various methods to forecast wind power,th...Accurate short-term wind power forecast technique plays a crucial role in maintaining the safety and economic efficiency of smart grids.Although numerous studies have employed various methods to forecast wind power,there remains a research gap in leveraging swarm intelligence algorithms to optimize the hyperparameters of the Transformer model for wind power prediction.To improve the accuracy of short-term wind power forecast,this paper proposes a hybrid short-term wind power forecast approach named STL-IAOA-iTransformer,which is based on seasonal and trend decomposition using LOESS(STL)and iTransformer model optimized by improved arithmetic optimization algorithm(IAOA).First,to fully extract the power data features,STL is used to decompose the original data into components with less redundant information.The extracted components as well as the weather data are then input into iTransformer for short-term wind power forecast.The final predicted short-term wind power curve is obtained by combining the predicted components.To improve the model accuracy,IAOA is employed to optimize the hyperparameters of iTransformer.The proposed approach is validated using real-generation data from different seasons and different power stations inNorthwest China,and ablation experiments have been conducted.Furthermore,to validate the superiority of the proposed approach under different wind characteristics,real power generation data fromsouthwestChina are utilized for experiments.Thecomparative results with the other six state-of-the-art prediction models in experiments show that the proposed model well fits the true value of generation series and achieves high prediction accuracy.展开更多
Sericin is a major silk protein, and recent studies have shown that sericin has numerous physiological activities against cultured cells. For example, it accelerates mammalian cell proliferation and protects insect ce...Sericin is a major silk protein, and recent studies have shown that sericin has numerous physiological activities against cultured cells. For example, it accelerates mammalian cell proliferation and protects insect cells against cell death. In this study, we examined the activities of sericin prepared from the wild silkworm, Cricula trifenestrata. The results presented here indicated that C. trifenestrata sericin has anti-proliferative activity against feline kidney cells, while sericin from Bombyx mori promoted cell proliferation. The components of the sericin preparation that played a role in inhibition of proliferation were analyzed by fractionation through partition chromatography (Folch method) and reversed-phase chromatography. Our analysis showed that at least two components in the C. trifenestrata sericin preparation promoted the anti-proliferative activity in an additive or even synergistic manner. Therefore, differences in components between insect species may contribute to different activities against cultured cells.展开更多
Background:Nasopharyngeal carcinoma(NPC)is one of the most prevalent cancers in Southeast Asia.Sirtuin 2(SIRT2)is a member of the NAD+-dependent deacetylase family and has been shown to play important roles in numerou...Background:Nasopharyngeal carcinoma(NPC)is one of the most prevalent cancers in Southeast Asia.Sirtuin 2(SIRT2)is a member of the NAD+-dependent deacetylase family and has been shown to play important roles in numerous biological processes.However,Its function in NPC remains uncertain.The primary aim of this study is to clarify the role of SIRT2 in NPC.Methods:In this research,we examined the effect of SIRT2 silencing on NPC cell proliferation and colony formation using vitro NPC cell lines.Co-immunoprecipitation and mass spectrometry was applied to identify SIRT2-interacting proteins in NPC cells.Results:In comparison to nasopharyngeal epithelial NP69 cells,SIRT2 was up-regulated in multiple NPC cell lines,particularly in CNE2 cells.SIRT2 knockdown abrogated CNE2 cell proliferation and colony formation,whereas SIRT2 overexpression promoted HNE1 cell proliferation and colony formation.The SIRT2-interacting proteins were gathered in gene expression and regulation processes including RNA processing and translation.Among the SIRT2-interacting proteins,there were multiple DEAD-box(DDX)family members.Of note,silencing of DDX24 phenocopied the effect of SIRT2 knockdown on NPC growth.Overexpression of DDX24 restored SIRT2-depleted CNE2 cells to proliferative and colony formation.Conclusions:Our study indicates that SIRT2 can interact with DDX24 to enhance NPC growth.The clinical relevance of SIRT2 and DDX24 in NPC warrants further investigation.展开更多
In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units int...In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units into tetracationic cyclophanes,resulting in enhanced host–vip recognition.The cyclophanes can be tuned through the addition of chalcogen bridging atoms—S,Se,and Te—which enhance their rigidity,regulate bond rotation and introduce additional steric bulk.Three cyclophanes containing chalcogen bridging atoms were synthesized and characterized in both the solution and solid states.The energy barriers for their interconversion between syn-and anti-conformations in solution were found to be correlated with chalcogen atom size.The photophysical properties of the cyclophanes are strongly dependent on the chalcogen atomic number,with intersystem crossing rates increasing from S to Se to Te.UV–vis-NIR spectroscopic and fluorometric titrations revealed that the chalcogenoviologenbased cyclophanes exhibit significantly stronger binding with electron-rich vips compared to the well-known,unsubstituted cyclobis(paraquat-pphenylene).This enhancement in binding can be attributed to restricted rotation within the chalcogenoviologen units.This research provides insight into the rational design and tailored synthesis of cationic cyclophanes.展开更多
In the light of the current problems of silver nanoparticles （Ag NPs） in terms of antibacterial performance, we have designed a novel trimetallic corelshell nanostructure with AgPt alloy nanodots epitaxially grown o...In the light of the current problems of silver nanoparticles （Ag NPs） in terms of antibacterial performance, we have designed a novel trimetallic corelshell nanostructure with AgPt alloy nanodots epitaxially grown on gold nanorods （Au@PtAg NRs） as a potential antibacterial agent. Both Escherichia coli （E. coli） and Staphylococcus aureus （S. aureus） were studied. The antibacterial activity exhibits an obvious composition-dependence. On increasing the Ag fraction in the alloy shell up to 80%, the antibacterial activity gradually increases, demonstrating a flexible way to tune this activity. At 80% Ag, tile antibacterial activity is better than that of a pure Ag shell. The improved antibacterial ability mainly results from the high exposure of silver on the shell surface due to the dot morphology. We thus demonstrate that forming alloys is an effective way to improve antibacterial activity while retaining high chemical stability for Ag-based nanomaterials. Furthermore, due to the tunable localized surface plasmonic response in the near-infrared （NIR） spectral region, additional control over antibacterial activity using light--such as photothermal killing and photo- triggered silver ion release--is expected. As a demonstration, highly enhanced antibacterial activity is shown by utilizing the NIR photothermal effect of the nanostructures. Our results indicate that such tailored nanostructures will find a role in the future fight against bacteria, including the challenge of the increasing severity of multidrug resistance.展开更多
Generation of circular dichroism （CD） beyond the UV region is of great interest in developing chiral sensors and chiroptical devices. Herein, we demonstrate a simple and versatile method for fabrication of plasmonic...Generation of circular dichroism （CD） beyond the UV region is of great interest in developing chiral sensors and chiroptical devices. Herein, we demonstrate a simple and versatile method for fabrication of plasmonic oligomers with strong CD response in the visible and near IR spectral range. The oligomers were fabricated by triggering the side-by-side assembly of cysteine-modified gold nanorods. The modified nanorods themselves did not exhibit obvious plasmonic CD signals; however, the oligomers show strong CD bands around the plasmon resonance wavelength. The sign of the CD band was dictated by the chirality of the absorbed cysteine molecules. By adjusting the size of the oligomers, the concentration of chiral molecules, and/or the aspect ratio of the nanorods, the CD intensity and spectral range were readily tunable. Theoretical calculations suggested that CD of the oligomers originated from a slight twist of adjacent nanorods within the oligomer. Therefore, we propose that the adsorbed chiral molecules are able to manipulate the twist angles between the nanorods and thus modulate the CD response of the oligomers.展开更多
Platinum nanoparticles （NPs） are reported to mimic various anfioxidant enzymes and thus may produce a positive biological effect by reducing reactive oxygen species （ROS） levels. In this manuscript, we report Pt N...Platinum nanoparticles （NPs） are reported to mimic various anfioxidant enzymes and thus may produce a positive biological effect by reducing reactive oxygen species （ROS） levels. In this manuscript, we report Pt NPs as an enzyme mimic of ferroxidase by depositing platinum nanodots on gold nanorods （Au@Pt NDRs）. Au@Pt NDRs show pH-dependent ferroxidase-like activity and have higher activity at neutral pH values. Cytotoxicity results with human cell lines （lung adenocarcinoma A549 and normal bronchial epithelial cell line HBE） show that Au@Pt NDRs are taken up into cells via endocytosis and translocate into the endosome/lysosome. Au@Pt NDRs have good biocompatibility at NDR particle concentrations lower than 0.15 nM. However, in the presence of H202, lysosome- located NDRs exhibit peroxidase-like activity and therefore increase cytotoxicity. In the presence of FeE＋, the ferroxidase-like activity of the NDRs protects cells from oxidative stress by consuming H202. Thorough consideration should be given to this behavior when employinK Au@Pt NDRs in biological svstems.展开更多
Pt and its based alloy nanoparticles(NPs)have been reported to demonstrate novel enzyme-like activities.Varying composition is very important to realize the optimization of their functions through the tuning of electr...Pt and its based alloy nanoparticles(NPs)have been reported to demonstrate novel enzyme-like activities.Varying composition is very important to realize the optimization of their functions through the tuning of electronic structure.In this paper,our effort is focused in this direction by tailoring the electronic structure of Pt NPs via alloying with copper.Using gold nanorod(Au NR)as core,a simple method to prepare PtCu alloy shell is developed(termed as Au@PtCu NR).The introduction of copper could result in endcap-preferred growth mode owing to the lattice mismatch between alloy shell and the Au core.The variation in the electronic structure changes the substrate affinity,and enhanced affinity was found for H2O2.Besides,the designed Au@PtCu nanostructures have realized spatial separation of catalytic and recognition sites.Binding of recognition antibodies had negligible effect on their catalytic activity.Based on their peroxidaselike activity,a highly sensitive detection of human immunoglobulin G(IgG)was demonstrated in a direct enzyme-linked immunosorbent assay(ELISA)mode.The detection limit can be as low as 90 pg/mL.展开更多
In this study, computer simulations are performed on three-dimensional granular systems under shear conditions. The system comprises granular particles that are confined between two rigid plates. The top plate is subj...In this study, computer simulations are performed on three-dimensional granular systems under shear conditions. The system comprises granular particles that are confined between two rigid plates. The top plate is subjected to a normal force and driven by a shearing velocity. A positive shear-rate dependence of granular friction, known as velocity-strengthening, exists between the granular and shearing plate. To understand the origin of the dependence of frictional sliding, we treat the granular system as a complex network, where granular particles are nodes and normal contact forces are weighted edges used to obtain insight into the interiors of granular matter. Community structures within granular property networks are detected under different shearing velocities in the steady state. Community parameters, such as the size of the largest cluster and average size of clusters, show significant monotonous trends in shearing velocity associated with the shear-rate dependence of granular friction. Then, we apply an instantaneous change in shearing velocity. A dramatic increase in friction is observed with a change in shearing velocity in the non-steady state. The community structures in the non-steady state are different from those in the steady state. Results indicate that the largest cluster is a key factor affecting the friction between the granular and shearing plate.展开更多
Purpose–Cooperative control of a group of unmanned aerial vehicles(UAVs)is an important area of research.The purpose of this paper is to explore multi-UAV control in the framework of providing surveillance of areas o...Purpose–Cooperative control of a group of unmanned aerial vehicles(UAVs)is an important area of research.The purpose of this paper is to explore multi-UAV control in the framework of providing surveillance of areas of interest with automatic loss detection and replacement capabilities.Design/methodology/approach–The research is based on the concept of the multi-agent system.The authors present the framework of the multi-agent and protocol design for monitoring the network of a group of UAVs.Findings–If one or more UAVs which is conducting a high priority surveillance task is lost,the system can self-arrange for another UAV to replace the lost UAV and continue to execute its task.This research provides an excellent design protocol for UAV loss detection and replacement scheme.Research limitations/implications–One of the major limitations of this research is that we have only two types of priority levels,high or low.If the priority is more than two levels,for example,high priority 1,high priority 2,or high priority 3,the replacement has not yet been implemented.Originality/value–This paper contributes to the following two aspects of the scientific knowledge.The first contribution is the design of an agent model which jointly considers system architecture,communication,control logic and target monitoring.The second contribution includes the decentralized and automatic UAV loss detection and replacement algorithm.展开更多
The properties of coordination complexes are dictated by both the metals and the ligands.The use of molecular receptors as second-sphere ligands enables significant modulation of the chemical and physical properties o...The properties of coordination complexes are dictated by both the metals and the ligands.The use of molecular receptors as second-sphere ligands enables significant modulation of the chemical and physical properties of coordination complexes.In this minireview,we highlight recent advances in functional systems based on molecular receptors as second-sphere coordination ligands,as applied in molecular recognition,synthesis of mechanically interlocked molecules,separation of metals,catalysis,and biomolecular chemistry.These functional systems demonstrate that second-sphere coordination is an emerging and very promising strategy for addressing societal challenges in health,energy,and the environment.展开更多
Herein,we found that anthraquinone(AQ)acted as a catalyst for the rapid and effective removal of triphenylmethane dye containing tertiary amino group(TDAG).Results showed that AQ had an enhanced catalytic reactivity t...Herein,we found that anthraquinone(AQ)acted as a catalyst for the rapid and effective removal of triphenylmethane dye containing tertiary amino group(TDAG).Results showed that AQ had an enhanced catalytic reactivity towards the removal of TDAG compared to hydro-quinone,which was further proved and explained using density functional theory(DFT)calculations.AQs could achieve a TDAG removal efficiency and rate of approximately 100%and 0.3583 min^(−1),respectively,within 20 min.Quenching experiments and electron paramagnetic resonance(EPR)tests indicated that the superoxide radical(O_(2)^(•−))generated through the catalytic reduction of an oxygen molecule(O_(2))by AQ contributed to the effective removal of the TDAG.In addition,itwas found that the electrophilic attack of the O_(2)^(•−)radical on the TDAG was the driving force for the dye degradation process.Decreasing the pH led to protonation of the substituted group of AG,which resulted in formation of an electron deficient center in the TDAGmolecule(TDAG-EDC+)through delocalization of the π electron.Therefore,the possibility of the electrophilic attack for the dye by the negative O_(2)^(•-)radical was significantly enhanced.This study revealed that the H+and the O_(2)^(•−)generated by the catalytic reduction of O_(2) have synergistic effects that led to a significant increase in the dye removal rate and efficiency,which were higher than those obtained through persulfate oxidation.展开更多
This paper examines the roadmap of interest rate liberalisation in China,including the current dual-track interest rate system and the future benchmark rate system.It provides a theoretical foundation for China to dev...This paper examines the roadmap of interest rate liberalisation in China,including the current dual-track interest rate system and the future benchmark rate system.It provides a theoretical foundation for China to develop its own benchmark interest rate.A vector autoregression model is estimated to investigate the effectiveness of Chinese market interest rates,Shanghai Interbank Offered Rate(SHIBOR),and repo rates against different factors such as market size,volatility,transmission channels of monetary policy,and term structures of interest rates.The result shows that SHIBOR affects both the market and the economy.As SHIBOR promptly reflects the changes in currency markets,we argue that it has the potential to become China’s benchmark interest rate.展开更多
基金supported by Yunnan Provincial Basic Research Project(202401AT070344,202301AT070443)National Natural Science Foundation of China(62263014,52207105)+1 种基金Yunnan Lancang-Mekong International Electric Power Technology Joint Laboratory(202203AP140001)Major Science and Technology Projects in Yunnan Province(202402AG050006).
文摘Accurate short-term wind power forecast technique plays a crucial role in maintaining the safety and economic efficiency of smart grids.Although numerous studies have employed various methods to forecast wind power,there remains a research gap in leveraging swarm intelligence algorithms to optimize the hyperparameters of the Transformer model for wind power prediction.To improve the accuracy of short-term wind power forecast,this paper proposes a hybrid short-term wind power forecast approach named STL-IAOA-iTransformer,which is based on seasonal and trend decomposition using LOESS(STL)and iTransformer model optimized by improved arithmetic optimization algorithm(IAOA).First,to fully extract the power data features,STL is used to decompose the original data into components with less redundant information.The extracted components as well as the weather data are then input into iTransformer for short-term wind power forecast.The final predicted short-term wind power curve is obtained by combining the predicted components.To improve the model accuracy,IAOA is employed to optimize the hyperparameters of iTransformer.The proposed approach is validated using real-generation data from different seasons and different power stations inNorthwest China,and ablation experiments have been conducted.Furthermore,to validate the superiority of the proposed approach under different wind characteristics,real power generation data fromsouthwestChina are utilized for experiments.Thecomparative results with the other six state-of-the-art prediction models in experiments show that the proposed model well fits the true value of generation series and achieves high prediction accuracy.
文摘Sericin is a major silk protein, and recent studies have shown that sericin has numerous physiological activities against cultured cells. For example, it accelerates mammalian cell proliferation and protects insect cells against cell death. In this study, we examined the activities of sericin prepared from the wild silkworm, Cricula trifenestrata. The results presented here indicated that C. trifenestrata sericin has anti-proliferative activity against feline kidney cells, while sericin from Bombyx mori promoted cell proliferation. The components of the sericin preparation that played a role in inhibition of proliferation were analyzed by fractionation through partition chromatography (Folch method) and reversed-phase chromatography. Our analysis showed that at least two components in the C. trifenestrata sericin preparation promoted the anti-proliferative activity in an additive or even synergistic manner. Therefore, differences in components between insect species may contribute to different activities against cultured cells.
基金supported by 2017 Guangxi Appropriate Technology Development and Application Project(S2017013)the Project of Guangxi Health Department(Grant Nos.Z20190059 and Z20181011).
文摘Background:Nasopharyngeal carcinoma(NPC)is one of the most prevalent cancers in Southeast Asia.Sirtuin 2(SIRT2)is a member of the NAD+-dependent deacetylase family and has been shown to play important roles in numerous biological processes.However,Its function in NPC remains uncertain.The primary aim of this study is to clarify the role of SIRT2 in NPC.Methods:In this research,we examined the effect of SIRT2 silencing on NPC cell proliferation and colony formation using vitro NPC cell lines.Co-immunoprecipitation and mass spectrometry was applied to identify SIRT2-interacting proteins in NPC cells.Results:In comparison to nasopharyngeal epithelial NP69 cells,SIRT2 was up-regulated in multiple NPC cell lines,particularly in CNE2 cells.SIRT2 knockdown abrogated CNE2 cell proliferation and colony formation,whereas SIRT2 overexpression promoted HNE1 cell proliferation and colony formation.The SIRT2-interacting proteins were gathered in gene expression and regulation processes including RNA processing and translation.Among the SIRT2-interacting proteins,there were multiple DEAD-box(DDX)family members.Of note,silencing of DDX24 phenocopied the effect of SIRT2 knockdown on NPC growth.Overexpression of DDX24 restored SIRT2-depleted CNE2 cells to proliferative and colony formation.Conclusions:Our study indicates that SIRT2 can interact with DDX24 to enhance NPC growth.The clinical relevance of SIRT2 and DDX24 in NPC warrants further investigation.
基金supported by the US Department of Energy,Office of Science,Office of Basic Energy Sciences,under Award DE-FG02-99ER14999(M.R.W.)This research made use of the Integrated Molecular Structure Education and Research Center NMR,MS,and X-ray facility at NU,which receives support from the Soft and Hybrid Nanotechnology Experimental(SHyNE)Resource(NSF ECCS-2025633)and NU(C.L.S.).
文摘In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units into tetracationic cyclophanes,resulting in enhanced host–vip recognition.The cyclophanes can be tuned through the addition of chalcogen bridging atoms—S,Se,and Te—which enhance their rigidity,regulate bond rotation and introduce additional steric bulk.Three cyclophanes containing chalcogen bridging atoms were synthesized and characterized in both the solution and solid states.The energy barriers for their interconversion between syn-and anti-conformations in solution were found to be correlated with chalcogen atom size.The photophysical properties of the cyclophanes are strongly dependent on the chalcogen atomic number,with intersystem crossing rates increasing from S to Se to Te.UV–vis-NIR spectroscopic and fluorometric titrations revealed that the chalcogenoviologenbased cyclophanes exhibit significantly stronger binding with electron-rich vips compared to the well-known,unsubstituted cyclobis(paraquat-pphenylene).This enhancement in binding can be attributed to restricted rotation within the chalcogenoviologen units.This research provides insight into the rational design and tailored synthesis of cationic cyclophanes.
文摘In the light of the current problems of silver nanoparticles （Ag NPs） in terms of antibacterial performance, we have designed a novel trimetallic corelshell nanostructure with AgPt alloy nanodots epitaxially grown on gold nanorods （Au@PtAg NRs） as a potential antibacterial agent. Both Escherichia coli （E. coli） and Staphylococcus aureus （S. aureus） were studied. The antibacterial activity exhibits an obvious composition-dependence. On increasing the Ag fraction in the alloy shell up to 80%, the antibacterial activity gradually increases, demonstrating a flexible way to tune this activity. At 80% Ag, tile antibacterial activity is better than that of a pure Ag shell. The improved antibacterial ability mainly results from the high exposure of silver on the shell surface due to the dot morphology. We thus demonstrate that forming alloys is an effective way to improve antibacterial activity while retaining high chemical stability for Ag-based nanomaterials. Furthermore, due to the tunable localized surface plasmonic response in the near-infrared （NIR） spectral region, additional control over antibacterial activity using light--such as photothermal killing and photo- triggered silver ion release--is expected. As a demonstration, highly enhanced antibacterial activity is shown by utilizing the NIR photothermal effect of the nanostructures. Our results indicate that such tailored nanostructures will find a role in the future fight against bacteria, including the challenge of the increasing severity of multidrug resistance.
文摘Generation of circular dichroism （CD） beyond the UV region is of great interest in developing chiral sensors and chiroptical devices. Herein, we demonstrate a simple and versatile method for fabrication of plasmonic oligomers with strong CD response in the visible and near IR spectral range. The oligomers were fabricated by triggering the side-by-side assembly of cysteine-modified gold nanorods. The modified nanorods themselves did not exhibit obvious plasmonic CD signals; however, the oligomers show strong CD bands around the plasmon resonance wavelength. The sign of the CD band was dictated by the chirality of the absorbed cysteine molecules. By adjusting the size of the oligomers, the concentration of chiral molecules, and/or the aspect ratio of the nanorods, the CD intensity and spectral range were readily tunable. Theoretical calculations suggested that CD of the oligomers originated from a slight twist of adjacent nanorods within the oligomer. Therefore, we propose that the adsorbed chiral molecules are able to manipulate the twist angles between the nanorods and thus modulate the CD response of the oligomers.
文摘Platinum nanoparticles （NPs） are reported to mimic various anfioxidant enzymes and thus may produce a positive biological effect by reducing reactive oxygen species （ROS） levels. In this manuscript, we report Pt NPs as an enzyme mimic of ferroxidase by depositing platinum nanodots on gold nanorods （Au@Pt NDRs）. Au@Pt NDRs show pH-dependent ferroxidase-like activity and have higher activity at neutral pH values. Cytotoxicity results with human cell lines （lung adenocarcinoma A549 and normal bronchial epithelial cell line HBE） show that Au@Pt NDRs are taken up into cells via endocytosis and translocate into the endosome/lysosome. Au@Pt NDRs have good biocompatibility at NDR particle concentrations lower than 0.15 nM. However, in the presence of H202, lysosome- located NDRs exhibit peroxidase-like activity and therefore increase cytotoxicity. In the presence of FeE＋, the ferroxidase-like activity of the NDRs protects cells from oxidative stress by consuming H202. Thorough consideration should be given to this behavior when employinK Au@Pt NDRs in biological svstems.
基金supported by the National NaturalScience Foundation of China(21173056)the National Key BasicResearch Program of China(2012CB934001,2011CB932802)
文摘Pt and its based alloy nanoparticles(NPs)have been reported to demonstrate novel enzyme-like activities.Varying composition is very important to realize the optimization of their functions through the tuning of electronic structure.In this paper,our effort is focused in this direction by tailoring the electronic structure of Pt NPs via alloying with copper.Using gold nanorod(Au NR)as core,a simple method to prepare PtCu alloy shell is developed(termed as Au@PtCu NR).The introduction of copper could result in endcap-preferred growth mode owing to the lattice mismatch between alloy shell and the Au core.The variation in the electronic structure changes the substrate affinity,and enhanced affinity was found for H2O2.Besides,the designed Au@PtCu nanostructures have realized spatial separation of catalytic and recognition sites.Binding of recognition antibodies had negligible effect on their catalytic activity.Based on their peroxidaselike activity,a highly sensitive detection of human immunoglobulin G(IgG)was demonstrated in a direct enzyme-linked immunosorbent assay(ELISA)mode.The detection limit can be as low as 90 pg/mL.
基金supported by the National Natural Science Foundation of China(Grant Nos.61573173,and 11504384)the Key Research Program of Frontier Sciences,Chinese Academy Sciences(Grant No.QYZDSSW-SYS019)the postdoctoral fellowship program funded by the Kunming University of Science and Technology
文摘In this study, computer simulations are performed on three-dimensional granular systems under shear conditions. The system comprises granular particles that are confined between two rigid plates. The top plate is subjected to a normal force and driven by a shearing velocity. A positive shear-rate dependence of granular friction, known as velocity-strengthening, exists between the granular and shearing plate. To understand the origin of the dependence of frictional sliding, we treat the granular system as a complex network, where granular particles are nodes and normal contact forces are weighted edges used to obtain insight into the interiors of granular matter. Community structures within granular property networks are detected under different shearing velocities in the steady state. Community parameters, such as the size of the largest cluster and average size of clusters, show significant monotonous trends in shearing velocity associated with the shear-rate dependence of granular friction. Then, we apply an instantaneous change in shearing velocity. A dramatic increase in friction is observed with a change in shearing velocity in the non-steady state. The community structures in the non-steady state are different from those in the steady state. Results indicate that the largest cluster is a key factor affecting the friction between the granular and shearing plate.
文摘Purpose–Cooperative control of a group of unmanned aerial vehicles(UAVs)is an important area of research.The purpose of this paper is to explore multi-UAV control in the framework of providing surveillance of areas of interest with automatic loss detection and replacement capabilities.Design/methodology/approach–The research is based on the concept of the multi-agent system.The authors present the framework of the multi-agent and protocol design for monitoring the network of a group of UAVs.Findings–If one or more UAVs which is conducting a high priority surveillance task is lost,the system can self-arrange for another UAV to replace the lost UAV and continue to execute its task.This research provides an excellent design protocol for UAV loss detection and replacement scheme.Research limitations/implications–One of the major limitations of this research is that we have only two types of priority levels,high or low.If the priority is more than two levels,for example,high priority 1,high priority 2,or high priority 3,the replacement has not yet been implemented.Originality/value–This paper contributes to the following two aspects of the scientific knowledge.The first contribution is the design of an agent model which jointly considers system architecture,communication,control logic and target monitoring.The second contribution includes the decentralized and automatic UAV loss detection and replacement algorithm.
基金The authors thank Northwestern University(NU)for their support of this work,which was also funded by the Center for Sustainable Separation of Metals(CSSM)and part of a National Science Foundation(NSF)Center for Chemical Innovation(CCI):grant number CHE1925708.
文摘The properties of coordination complexes are dictated by both the metals and the ligands.The use of molecular receptors as second-sphere ligands enables significant modulation of the chemical and physical properties of coordination complexes.In this minireview,we highlight recent advances in functional systems based on molecular receptors as second-sphere coordination ligands,as applied in molecular recognition,synthesis of mechanically interlocked molecules,separation of metals,catalysis,and biomolecular chemistry.These functional systems demonstrate that second-sphere coordination is an emerging and very promising strategy for addressing societal challenges in health,energy,and the environment.
基金supported by the Strategic Research and Development Program of Shaanxi Province (No. 2019ZDLSF06-02)the Special Project for Serving Local S&T Development of Education Department, Shaanxi Province (No. 21JC022)。
文摘Herein,we found that anthraquinone(AQ)acted as a catalyst for the rapid and effective removal of triphenylmethane dye containing tertiary amino group(TDAG).Results showed that AQ had an enhanced catalytic reactivity towards the removal of TDAG compared to hydro-quinone,which was further proved and explained using density functional theory(DFT)calculations.AQs could achieve a TDAG removal efficiency and rate of approximately 100%and 0.3583 min^(−1),respectively,within 20 min.Quenching experiments and electron paramagnetic resonance(EPR)tests indicated that the superoxide radical(O_(2)^(•−))generated through the catalytic reduction of an oxygen molecule(O_(2))by AQ contributed to the effective removal of the TDAG.In addition,itwas found that the electrophilic attack of the O_(2)^(•−)radical on the TDAG was the driving force for the dye degradation process.Decreasing the pH led to protonation of the substituted group of AG,which resulted in formation of an electron deficient center in the TDAGmolecule(TDAG-EDC+)through delocalization of the π electron.Therefore,the possibility of the electrophilic attack for the dye by the negative O_(2)^(•-)radical was significantly enhanced.This study revealed that the H+and the O_(2)^(•−)generated by the catalytic reduction of O_(2) have synergistic effects that led to a significant increase in the dye removal rate and efficiency,which were higher than those obtained through persulfate oxidation.
文摘This paper examines the roadmap of interest rate liberalisation in China,including the current dual-track interest rate system and the future benchmark rate system.It provides a theoretical foundation for China to develop its own benchmark interest rate.A vector autoregression model is estimated to investigate the effectiveness of Chinese market interest rates,Shanghai Interbank Offered Rate(SHIBOR),and repo rates against different factors such as market size,volatility,transmission channels of monetary policy,and term structures of interest rates.The result shows that SHIBOR affects both the market and the economy.As SHIBOR promptly reflects the changes in currency markets,we argue that it has the potential to become China’s benchmark interest rate.
