Objective To investigate the serum total IgE （tlgE） and specific IgE （slgE） to common allergens among allergic patients in Guangzhou, China. Methods 7 085 patients were examined for tlgE and slgE to 15 allergens, ...Objective To investigate the serum total IgE （tlgE） and specific IgE （slgE） to common allergens among allergic patients in Guangzhou, China. Methods 7 085 patients were examined for tlgE and slgE to 15 allergens, based on the protocols of reversed enzyme allergosorbent test and the sandwich enzyme-linked immunosorbent assay. Results 3 758 （53.04%） patients tested positive for tlgE, and 4 640 （65.49%） for slgE. Der pteronyssinus, Derfarinae, eggs, and cow＇s milk were the most common allergens leading to higher positive rates of slgE responses. Several peaks of sensitization were： Der pteronyssinus, Derfarinae, and Blomia tropicalis at age 10-12; cow＇s milk at age below 3; eggs at age 4-6. The mean level and positive rate of tlgE tended to increase in subjects sensitized to more allergens. Sensitization to Der pteronyssinus （OR, 1.6; P〈O.05）, Der farinae （OR, 1.5; P〈O.05）, Blomia tropicalis （OR, 1.4; P〈O.05）, Blattella germanica （OR, 1.5; P〈O.05）, cow＇s milk （OR, 1.3; P〈O.05）, and soy beans （OR, 2.0; P〈O.05） were independently correlated with allergy-related conditions in preliminary diagnosis. Conclusion The major allergens in Guangzhou include Derpteronyssinus, Derfarinae, cow＇s milk, and eggs. Sensitization to these allergens appears to be predictors of allergy-related disorder.展开更多
In recent years,the usage,management and benefit of large-scale scientific research instruments and equipment in scientific research institutes have been a leading issue in the management of scientific research instit...In recent years,the usage,management and benefit of large-scale scientific research instruments and equipment in scientific research institutes have been a leading issue in the management of scientific research institutes.Within the scope of equipment budget,it is necessary for each equipment acquisition team to conduct a round of communication,coordination and negotiation with suppliers in order to improve the cost performance of equipment procurement and maximize the performance index to meet the needs of scientific research.By introducing the practical experience of the State Key Laboratory in purchasing imported equipment and managing large-scale instruments,this paper probes into the management process of the imported large-scale scientific research tax-free equipment of scientific research institutes,and explores the system and methods to guarantee and improve the efficiency of large-scale instruments in scientific research institutes from the aspects of policy,funds and technology.展开更多
The State Key Laboratory of Natural and Biomimetic Drugs was approved for a funding of nearly 100 million yuan specifically aimed at the purchase and maintenance of equipment and instruments from 2018 to 2020,which is...The State Key Laboratory of Natural and Biomimetic Drugs was approved for a funding of nearly 100 million yuan specifically aimed at the purchase and maintenance of equipment and instruments from 2018 to 2020,which is a record high.The Laboratory focuses on two major directions of scientific research,the"basic scientific problems of drug resistance of complex components of natural products"and the"key biomimetic scientific problems of endogenous substances therapeutic functions".The selection of scientific instruments and equipment,trial production,upgrading,as well as high level of technical and management personnel allocation and other aspects are critical to meet the development needs of the Key Laboratory and to maintain the advantages and leading role in these two major directions of scientific research.展开更多
This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT w...This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT was the Center for Display Research(CDR)which was started in 1995.Thus display research has a long history at HKUST.展开更多
·Prof.XIONG,could you please give us a brief introduction to SKLMCMS？Director XIONG Ke：The State Key Laboratory of Mechanics and Control of Mechanical Structures（SKLMCMS）was established with the approval of t...·Prof.XIONG,could you please give us a brief introduction to SKLMCMS？Director XIONG Ke：The State Key Laboratory of Mechanics and Control of Mechanical Structures（SKLMCMS）was established with the approval of the Ministry of Science and Technology of the People’s Republic of China in October 2011.The laboratory is located at Nanjing University of Aeronautics and Astronautics（NUAA）.展开更多
The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power sys...The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power system with REGs.In this paper,the critical short circuit ratio(CSCR)is defined as the corresponding SCR when the system voltage is in the critical stable state.Through static voltage stability analysis,the mathematical expression of the CSCR considering the impact of GIR is derived.The maximum value of CSCR is adopted as the critical value to distinguish the weak power system.Based on the static equivalent circuit analysis,it is proved that the CSCR is still effective to evaluate critical system strength considering the interactive impact among REGs.Finally,we find that the GIR can be neglected and the SCR can be used individually to evaluate the system strength when SCR>2 or GIR>5.The correctness and rationality of the CSCR and its critical value are validated on ADPSS.展开更多
Penthorum chinense Pursh has been used for centuries as an herbal medicine and food in East Asia.The main active substances in P.chinense are galloylated macrocyclic polyphenolic compounds,which have excellent medicin...Penthorum chinense Pursh has been used for centuries as an herbal medicine and food in East Asia.The main active substances in P.chinense are galloylated macrocyclic polyphenolic compounds,which have excellent medicinal properties.Galloylation and glycosylation are key steps in the formation of polyphenolic compounds,as the glycosylation of flavonoids is required for the acylation of flavonoid glycosides,and the glycosylation of gallic acid is necessary for its role as an acyl donor.Therefore,glycosylation to generate the acyl donor or acceptor is a core step in the biosynthesis of polyphenolic compounds.However,how this glycosylation occurs in P.chinense is unknown.In this study,we determined that the UDP-glucose transferase PcUGT84A82 mediates the glycosylation of gallic acid and pinocembrin to produce 1-O-Galloyl-β-D-glucose and pinocembroside,respectively.Metabolic profiling of polyphenolic compounds using UHPLC-ESI–Q-TOF/MS revealed high levels of polyphenols in flowers,leaves,and roots,and low levels in stems of P.chinense.We performed isoform-sequencing(Iso-seq)to assemble a full-length transcriptome of P.chinense,from which we identified 58 UGT family members.PcUGT84A82 is highly similar to functional UGTs in other plant species,and PcUGT84A82 transcript levels were positively correlated with the levels of various polyphenolic compounds.We validated the function of PcUGT84A82 via in vitro enzyme assays and transient expression in Nicotiana benthamiana leaves.Subcellular localization tests showed that PcUGT84A82 localizes to the nucleus and cytoplasm.In summary,PcUGT84A82 catalyzes the conversion of gallic acid to 1-O-Galloyl-β-D-glucose as the acyl donor and pinocembrin to pinocembroside as the acyl acceptor,mediating the biosynthesis of galloylated macrocyclic polyphenolic compounds in P.chinense.These findings lay the foundation for elucidating the entire biosynthetic pathway of active polyphenols in this important herbal plant species.展开更多
Phase-matching quantum-key distribution(PM-QKD)has achieved significant results in various practical applications.However,real-time communication requires dynamic adjustment and optimization of key parameters during c...Phase-matching quantum-key distribution(PM-QKD)has achieved significant results in various practical applications.However,real-time communication requires dynamic adjustment and optimization of key parameters during communication.In this letter,we predict the PM-QKD parameters using nature-inspired algorithms(NIAs).The results are obtained from an exhaustive traversal algorithm(ETA),which serves as a benchmark.We mainly study the parameter optimization effects of the two NIAs:ant colony optimization(ACO)and the genetic algorithm(GA).The configuration of the inherent parameters of these algorithms in the decoy-state PM-QKD is also discussed.The simulation results indicate that the parameters obtained by the ACO exhibit superior convergence and stability,whereas the GA results are relatively scattered.Nevertheless,more than 97%of the key rates predicted by both algorithms are highly consistent with the optimal key rate.Moreover,the relative error of the key rates remained below 10%.Furthermore,NIAs maintain power consumption below 8 W and require three orders of magnitude less computing time than ETA.展开更多
EngineeringAsking good questions is often a starting point of a revolutionary breakthrough.Good examples include the famous 7 Clay millennium problems and the 125 open questions released in SCIENCE in 2021 at the 125t...EngineeringAsking good questions is often a starting point of a revolutionary breakthrough.Good examples include the famous 7 Clay millennium problems and the 125 open questions released in SCIENCE in 2021 at the 125th anniversary of Shanghai Jiaotong University(SJTU),which greatly promote the development in mathematics,science and technology.展开更多
Fiber materials are essential to national economic growth,people’s livelihoods,and social progress.They have been widely used in clothing,aerospace,energy devices,flexible electronics,tissue engineering,and many othe...Fiber materials are essential to national economic growth,people’s livelihoods,and social progress.They have been widely used in clothing,aerospace,energy devices,flexible electronics,tissue engineering,and many other fields.The chemical fiber industry of China was underdeveloped before the early 1980s,and even could not produce enough chemical fiber products for clothing.展开更多
Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and conti...Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and continuous innovation are indispensable for sustaining a competitive advantage in technological development,thereby securing national scientific capacity and long-term strategic growth.At present,however,China faces substantial risks of technological"stranglehold"in the high-end scientific instrument domain.The underlying causes are multifaceted,arising not only from insufficient accumulation of core technologies but also from entrenched systemic and ecosystem-level barriers that impede the application,scaling,and promotion of domestic instruments.This paper provides a systematic analysis of the challenges hindering the widespread adoption of domestically developed scientific instruments and proposes practical pathways to build a new,integrated"R&D-application-promotion"ecosystem.This ecosystem is anchored in trust,driven by user demand,and shaped through collaborative innovation.Key initiatives include organizing user visits to instrument manufacturers,convening seminars on domestic alternatives to imported equipment,establishing demonstration centers for application and promotion,and involving end-users directly in the R&D and iterative upgrading of domestic instruments.Together,these efforts aim to close the final critical gap,advancing domestic instruments from merely"functional"to genuinely"user-friendly",and ultimately to"widely implemented".By doing so,this framework offers both theoretical grounding and practical guidance for achieving high-level scientific and technological self-reliance and sustained innovation capacity.展开更多
The dense heterogeneous network provides standardized connectivity and access guarantees for 5G communication services.However,the complex network environment and high level of dynamism pose challenges to network sele...The dense heterogeneous network provides standardized connectivity and access guarantees for 5G communication services.However,the complex network environment and high level of dynamism pose challenges to network selection decisions.Existing vertical handover algorithms often overlook the dynamic nature of user mobility and network condition,resulting in problems such as handover failure and frequent handover,ultimately impacting the quality of the user communication service.To address these problems,we propose an intelligent switching method,iMALSTM-DQN,which integrates an improved Multi-level Associative Long Short-Term Memory model(iMALSTM)with Deep Reinforcement Learning(DRL).The algorithm leverages iMALSTM to predict the global network state in the next moment based on the global user movement trajectory and historical network status information within a region,thereby enhancing the prediction accuracy of network states.Subsequently,based on the predicted network state,we employ the Deep Q Network(DON)model to make handover decisions,adaptively determining the optimal switching and network selection strategy through interaction with the environment.Experimental results demonstrate that the proposed algorithm enhances decision timeliness,significantly reduces the number of switch failures,and alleviates the problem of frequent handovers resulting from network dynamics.展开更多
Solid-state sodium batteries(SSSBs)have been highly prized as a promising alternative to conventional battery systems using organic liquid electrolytes due to their improved safety,higher energy density,and substantia...Solid-state sodium batteries(SSSBs)have been highly prized as a promising alternative to conventional battery systems using organic liquid electrolytes due to their improved safety,higher energy density,and substantial resources and low cost of sodium.Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)solid electrolyte is attracting considerable interest owing to its excellent thermal and chemical stability and favorable compatibility with Na metal anode and high-voltage cathode.However,two main challenges of poor roomtemperature ionic conductivity and high interfacial resistance limit the application of NZSP electrolyte in SSSBs.So far,intensive efforts have been devoted to developing modification strategies to improve the room-temperature ionic conductivity of NZSP.This review aims to provide a comprehensive summary and discussion of some optimization strategies for enhancing the room-temperature ionic conductivity of the NZSP solid electrolyte.These optimization strategies are categorized into foreignion doping or substitution,sintering behavior modulation,and regulation of chemical composition based on precursors,and their optimization mechanisms are also elaborated.Finally,the prospects of NZSP-based solid electrolytes are presented.This review is expected to offer better guidance for designing and developing high-performance NZSP-based solid electrolytes for accelerating the practical application of SSSBs.展开更多
This study investigates the mechanisms of friction-induced vibration under periodic variations in stress distribution using an improved fretting friction model.A fretting friction test system integrated with a total r...This study investigates the mechanisms of friction-induced vibration under periodic variations in stress distribution using an improved fretting friction model.A fretting friction test system integrated with a total reflection method was developed to analyze interfacial contact behavior under dynamic loading conditions.An improved fretting friction model was established,incorporating three critical nonlinear parameters:the hysteretic friction coefficient,tangential stiffness fluctuations,and stress distribution.Through systematic validation,the model demonstrates high-fidelity replication of experimental steady-state amplitude-frequency responses.Key findings reveal that non-uniform stress distribution governs irregularities in the vibration response,and increased uniformity intensifies stick-slip instabilities.Near the stick-slip transition threshold,distinct vibration anomalies emerge due to the coupled effects of stress heterogeneity,friction hysteresis,and stiffness variations during state transitions.Furthermore,the magnitude of the normal contact force systematically alters the dominant interfacial contact mechanism.The different interfacial contact states at various frequencies lead to distinct steady-state responses.This shift elevates resonance frequencies and amplifies higher-order resonant peaks.The fretting friction model provides a predictive framework for vibration control under dynamic interfacial loading.展开更多
High-nickel cathode,LiNi0.8Co0.1Mn0.1O_(2)(NCM811),and sulfide-solid electrolyte are a promising combination for all-solid-state lithium batteries(ASSLBs).However,this combination faces the issue of interfacial instab...High-nickel cathode,LiNi0.8Co0.1Mn0.1O_(2)(NCM811),and sulfide-solid electrolyte are a promising combination for all-solid-state lithium batteries(ASSLBs).However,this combination faces the issue of interfacial instability between the cathode and electrolyte.Given the surface alkalinity of NCM811,we propose a strategy to construct a solid-polymer-electrolyte(SPE)interphase on NCM811 surface by leveraging the surface alkaline residues to nucleophilically initiate the in-situ ring-opening polymerization of cyclic organic molecules.As a proof-of-concept,this study demonstrates that the ring-opening copolymerization of 1,3-dioxolane and maleic anhydride produces a homogeneous,compact,and conformal SPE layer on NCM811 surface to prevent the cathode from contact and reaction with Li6PS5Cl solid-state electrolyte.Consequently,the SPE-modified-NCM811 in ASSLBs exhibits high capacities of 193.5 mA h g^(-1) at 0.2 C,160.9 mA h g^(-1) at 2.0 C and 112.3 mA h g^(-1) at 10 C,and particularly,excellent long-term cycling stabilities over 11000 cycles with a 71.95%capacity retention at 10 C at 25℃,as well as a remained capacity of 117.9 mA h g^(-1) after 8000 cycles at 30 C at 60℃,showing a great application prospect.This study provides a new route for creating electrochemically and structurally stable solid-solid interfaces for ASSLBs.展开更多
State constraints in nonlinear systems are commonly pursued by resorting to barrier functions,which enforce constraints over the entire duration of system operation.We propose a universal intermittent state-constraine...State constraints in nonlinear systems are commonly pursued by resorting to barrier functions,which enforce constraints over the entire duration of system operation.We propose a universal intermittent state-constrained solution,which not only offers flexibility by activating constraints just during specific time periods of interest to the user,but also successfully accommodates different types of constraint boundaries.The innovative shifting functions are proposed to facilitate seamless transitions between constrained and unconstrained operational phases,resulting in more user-friendly design and implementation.By blending an improved shifting transformation into intermittent constraint design,we construct a universal barrier function upon the constrained states,with which our control strategy removes the limitations on constraint functions and completely obviates the feasibility conditions.Furthermore,a modified fuzzy approximator driven by the prediction error rather than the tracking error achieves decoupling of the control and estimation loops,which not only ensures the estimation performance,but also facilitates proof of stability.Finally,the effectiveness of the proposed scheme is assessed by numerical simulation.展开更多
Legume-based intercropping enhances asymbiotic biological nitrogen fixation(BNF);however,the underlying mechanisms remain unclear,including the roles of soil keystone diazotroph taxa with varying niche breadths.A fiel...Legume-based intercropping enhances asymbiotic biological nitrogen fixation(BNF);however,the underlying mechanisms remain unclear,including the roles of soil keystone diazotroph taxa with varying niche breadths.A field experiment was conducted to evaluate soil BNF variations between rhizosphere and bulk soils in peanut/cotton intercropping systems and monocultures.BNF activities were measured by nitrogen fixation rates,nitrogenase activity,and nifH gene abundance.Phylogenetic null models,co-occurrence networks,and niche breadth analysis were applied to investigate the roles of diazotrophic keystone taxa and their ecological niches.Rhizosphere soils exhibited 7.8–125.5%higher BNF potentials than bulk soils,whereas intercropping systems showed 11.6–323.0%increases over monocultures for nitrogen fixation rate,nitrogenase activity,and nifH gene abundance(all P<0.05).Diazotrophic community composition and diversity differed significantly,with Proteobacteria(excluding Alphaproteobacteria)enriched in intercropping and rhizosphere soils,while Cyanobacteria and Firmicutes were less abundant.Deterministic processes,particularly heterogeneous selection,dominated community assembly in the rhizosphere(91.9%)and intercropping soils(86.3%).The co-occurrence networks consistently revealed more complex and interconnected communities in intercropping and rhizosphere soils that were dominated by opportunistic diazotrophs(78.8–85.9%),followed by specialists(10.2–18.5%)and generalists(1.38–3.80%).Keystone taxa,including opportunists such as Azoarcus,Azohydromonas,and Steroidobacter,and generalists like Pseudomonas and Azotobacter,correlated positively with microbial biomass carbon and nitrate nitrogen,contributing to enhanced BNF.Peanut/cotton intercropping enhances BNF by selectively enriching the keystone diazotrophic taxa with varying ecological roles,particularly opportunists and generalists.Such targeted intercropping strategies can optimize BNF,improve soil fertility,and promote sustainable agricultural production.展开更多
Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To under...Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To understand these complex heat recovery processes,we simulated long-term heat extraction in a surrogate HDR using a true triaxial apparatus.A circulation test was first implemented to analyze the connectivity between different wells.Suitable injection and production wells were then selected for the laboratory heat extraction tests in granite,which lasted 14.5 h.Under variable injection rate conditions,we systematically analyzed the time-varying curves of temperature and flow rate in the production wells and pressure in the injection wells.Our findings showed that the advantage channel was dominant in the flow distribution when several paths existed in EGS.Changes in fracture conductivity are attributed to injection pressure.These included an increase in fracture width and activation of a localized closed area of fracture.These two mechanisms influenced the production temperature,and this is consistent with the field data monitored at the Fenton Hill and Hijiori projects.Fluid leak-off was an important factor affecting the production flow rate.For a fracture with low hydraulic conductivity,a lower injection rate could effectively prevent excessive fluid leak-off.In addition,by comparing injection rates and fluid recovery rates,production wells in different phases or injection modes had different fluid recovery rates even when the injection rates were the same.展开更多
The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice sp...The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice space and the reflection-asymmetric triaxial particle rotor model.It is found that^(229)Th has a ground state with static axial octupole and quadrupole deformations.The occurrence of octupole correlations,driven by the octupole deformation,is analyzed through the evolution of single-particle levels around the Fermi surface.The experimental energy spectrum and the electromagnetic transition probabilities,including B(E2)and B(M1),are reasonably well reproduced.展开更多
基金supported by Guangdong Industry Technology and Development Fund(No.2011B061200040)Science Foundation of Guangzhou Medical Univesity(Project No.2013A06)Guangdong Natural Science Foundation(No.S2013010014728)
文摘Objective To investigate the serum total IgE （tlgE） and specific IgE （slgE） to common allergens among allergic patients in Guangzhou, China. Methods 7 085 patients were examined for tlgE and slgE to 15 allergens, based on the protocols of reversed enzyme allergosorbent test and the sandwich enzyme-linked immunosorbent assay. Results 3 758 （53.04%） patients tested positive for tlgE, and 4 640 （65.49%） for slgE. Der pteronyssinus, Derfarinae, eggs, and cow＇s milk were the most common allergens leading to higher positive rates of slgE responses. Several peaks of sensitization were： Der pteronyssinus, Derfarinae, and Blomia tropicalis at age 10-12; cow＇s milk at age below 3; eggs at age 4-6. The mean level and positive rate of tlgE tended to increase in subjects sensitized to more allergens. Sensitization to Der pteronyssinus （OR, 1.6; P〈O.05）, Der farinae （OR, 1.5; P〈O.05）, Blomia tropicalis （OR, 1.4; P〈O.05）, Blattella germanica （OR, 1.5; P〈O.05）, cow＇s milk （OR, 1.3; P〈O.05）, and soy beans （OR, 2.0; P〈O.05） were independently correlated with allergy-related conditions in preliminary diagnosis. Conclusion The major allergens in Guangzhou include Derpteronyssinus, Derfarinae, cow＇s milk, and eggs. Sensitization to these allergens appears to be predictors of allergy-related disorder.
文摘In recent years,the usage,management and benefit of large-scale scientific research instruments and equipment in scientific research institutes have been a leading issue in the management of scientific research institutes.Within the scope of equipment budget,it is necessary for each equipment acquisition team to conduct a round of communication,coordination and negotiation with suppliers in order to improve the cost performance of equipment procurement and maximize the performance index to meet the needs of scientific research.By introducing the practical experience of the State Key Laboratory in purchasing imported equipment and managing large-scale instruments,this paper probes into the management process of the imported large-scale scientific research tax-free equipment of scientific research institutes,and explores the system and methods to guarantee and improve the efficiency of large-scale instruments in scientific research institutes from the aspects of policy,funds and technology.
文摘The State Key Laboratory of Natural and Biomimetic Drugs was approved for a funding of nearly 100 million yuan specifically aimed at the purchase and maintenance of equipment and instruments from 2018 to 2020,which is a record high.The Laboratory focuses on two major directions of scientific research,the"basic scientific problems of drug resistance of complex components of natural products"and the"key biomimetic scientific problems of endogenous substances therapeutic functions".The selection of scientific instruments and equipment,trial production,upgrading,as well as high level of technical and management personnel allocation and other aspects are critical to meet the development needs of the Key Laboratory and to maintain the advantages and leading role in these two major directions of scientific research.
文摘This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT was the Center for Display Research(CDR)which was started in 1995.Thus display research has a long history at HKUST.
文摘·Prof.XIONG,could you please give us a brief introduction to SKLMCMS？Director XIONG Ke：The State Key Laboratory of Mechanics and Control of Mechanical Structures（SKLMCMS）was established with the approval of the Ministry of Science and Technology of the People’s Republic of China in October 2011.The laboratory is located at Nanjing University of Aeronautics and Astronautics（NUAA）.
基金supported by the Science and Technology Project of State Grid Corporation of China(No.XT71-20-014).
文摘The power system is experiencing a higher penetration of renewable energy generations(REGs).The short circuit ratio(SCR)and the grid impedance ratio(GIR)are two indices to quantify the system strength of the power system with REGs.In this paper,the critical short circuit ratio(CSCR)is defined as the corresponding SCR when the system voltage is in the critical stable state.Through static voltage stability analysis,the mathematical expression of the CSCR considering the impact of GIR is derived.The maximum value of CSCR is adopted as the critical value to distinguish the weak power system.Based on the static equivalent circuit analysis,it is proved that the CSCR is still effective to evaluate critical system strength considering the interactive impact among REGs.Finally,we find that the GIR can be neglected and the SCR can be used individually to evaluate the system strength when SCR>2 or GIR>5.The correctness and rationality of the CSCR and its critical value are validated on ADPSS.
基金the National Natural Science Foundation of China(82304659)a Chenguang Project of Shanghai(23CGA52)+2 种基金the Shanghai Municipal Science and Technology Commission 2025 Key Technology R&D Program“Synthetic Biology”Project(25HC2810300)the Key Project at Central Government Level:the Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources(2060302)the Science and Technology Development Program of Shanghai University of Traditional Chinese Medicine(23KFL045,23KFL051).
文摘Penthorum chinense Pursh has been used for centuries as an herbal medicine and food in East Asia.The main active substances in P.chinense are galloylated macrocyclic polyphenolic compounds,which have excellent medicinal properties.Galloylation and glycosylation are key steps in the formation of polyphenolic compounds,as the glycosylation of flavonoids is required for the acylation of flavonoid glycosides,and the glycosylation of gallic acid is necessary for its role as an acyl donor.Therefore,glycosylation to generate the acyl donor or acceptor is a core step in the biosynthesis of polyphenolic compounds.However,how this glycosylation occurs in P.chinense is unknown.In this study,we determined that the UDP-glucose transferase PcUGT84A82 mediates the glycosylation of gallic acid and pinocembrin to produce 1-O-Galloyl-β-D-glucose and pinocembroside,respectively.Metabolic profiling of polyphenolic compounds using UHPLC-ESI–Q-TOF/MS revealed high levels of polyphenols in flowers,leaves,and roots,and low levels in stems of P.chinense.We performed isoform-sequencing(Iso-seq)to assemble a full-length transcriptome of P.chinense,from which we identified 58 UGT family members.PcUGT84A82 is highly similar to functional UGTs in other plant species,and PcUGT84A82 transcript levels were positively correlated with the levels of various polyphenolic compounds.We validated the function of PcUGT84A82 via in vitro enzyme assays and transient expression in Nicotiana benthamiana leaves.Subcellular localization tests showed that PcUGT84A82 localizes to the nucleus and cytoplasm.In summary,PcUGT84A82 catalyzes the conversion of gallic acid to 1-O-Galloyl-β-D-glucose as the acyl donor and pinocembrin to pinocembroside as the acyl acceptor,mediating the biosynthesis of galloylated macrocyclic polyphenolic compounds in P.chinense.These findings lay the foundation for elucidating the entire biosynthetic pathway of active polyphenols in this important herbal plant species.
基金supported by the State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)No.IPOC2021ZT10BUPT Excellent Ph.D.Students Foundation(Grant No.CX2023207)the BUPT innovation and entrepreneurship support program No.2024-YC-A188。
文摘Phase-matching quantum-key distribution(PM-QKD)has achieved significant results in various practical applications.However,real-time communication requires dynamic adjustment and optimization of key parameters during communication.In this letter,we predict the PM-QKD parameters using nature-inspired algorithms(NIAs).The results are obtained from an exhaustive traversal algorithm(ETA),which serves as a benchmark.We mainly study the parameter optimization effects of the two NIAs:ant colony optimization(ACO)and the genetic algorithm(GA).The configuration of the inherent parameters of these algorithms in the decoy-state PM-QKD is also discussed.The simulation results indicate that the parameters obtained by the ACO exhibit superior convergence and stability,whereas the GA results are relatively scattered.Nevertheless,more than 97%of the key rates predicted by both algorithms are highly consistent with the optimal key rate.Moreover,the relative error of the key rates remained below 10%.Furthermore,NIAs maintain power consumption below 8 W and require three orders of magnitude less computing time than ETA.
文摘EngineeringAsking good questions is often a starting point of a revolutionary breakthrough.Good examples include the famous 7 Clay millennium problems and the 125 open questions released in SCIENCE in 2021 at the 125th anniversary of Shanghai Jiaotong University(SJTU),which greatly promote the development in mathematics,science and technology.
文摘Fiber materials are essential to national economic growth,people’s livelihoods,and social progress.They have been widely used in clothing,aerospace,energy devices,flexible electronics,tissue engineering,and many other fields.The chemical fiber industry of China was underdeveloped before the early 1980s,and even could not produce enough chemical fiber products for clothing.
基金Management Research Project on the Transformation of Scientific and Technological Achievements at Peking University Health Science Center(Grant No.KT202501)Peking University Health Science Center 2025 Party Building Research Project(General Category,No.2)。
文摘Scientific instruments serve as foundational pillars for both scientific progress and industrial innovation,enabling deep exploration and driving technological breakthroughs.Their independent controllability and continuous innovation are indispensable for sustaining a competitive advantage in technological development,thereby securing national scientific capacity and long-term strategic growth.At present,however,China faces substantial risks of technological"stranglehold"in the high-end scientific instrument domain.The underlying causes are multifaceted,arising not only from insufficient accumulation of core technologies but also from entrenched systemic and ecosystem-level barriers that impede the application,scaling,and promotion of domestic instruments.This paper provides a systematic analysis of the challenges hindering the widespread adoption of domestically developed scientific instruments and proposes practical pathways to build a new,integrated"R&D-application-promotion"ecosystem.This ecosystem is anchored in trust,driven by user demand,and shaped through collaborative innovation.Key initiatives include organizing user visits to instrument manufacturers,convening seminars on domestic alternatives to imported equipment,establishing demonstration centers for application and promotion,and involving end-users directly in the R&D and iterative upgrading of domestic instruments.Together,these efforts aim to close the final critical gap,advancing domestic instruments from merely"functional"to genuinely"user-friendly",and ultimately to"widely implemented".By doing so,this framework offers both theoretical grounding and practical guidance for achieving high-level scientific and technological self-reliance and sustained innovation capacity.
基金National Key Research and Development Program of China(No.2022YFB3903404,2024YFC3015403)National Natural Science Foundation of China(NSFC No.42271431,42271425)Hubei Province Major Science and Technology Innovation Program(2024BAA011)。
文摘The dense heterogeneous network provides standardized connectivity and access guarantees for 5G communication services.However,the complex network environment and high level of dynamism pose challenges to network selection decisions.Existing vertical handover algorithms often overlook the dynamic nature of user mobility and network condition,resulting in problems such as handover failure and frequent handover,ultimately impacting the quality of the user communication service.To address these problems,we propose an intelligent switching method,iMALSTM-DQN,which integrates an improved Multi-level Associative Long Short-Term Memory model(iMALSTM)with Deep Reinforcement Learning(DRL).The algorithm leverages iMALSTM to predict the global network state in the next moment based on the global user movement trajectory and historical network status information within a region,thereby enhancing the prediction accuracy of network states.Subsequently,based on the predicted network state,we employ the Deep Q Network(DON)model to make handover decisions,adaptively determining the optimal switching and network selection strategy through interaction with the environment.Experimental results demonstrate that the proposed algorithm enhances decision timeliness,significantly reduces the number of switch failures,and alleviates the problem of frequent handovers resulting from network dynamics.
基金National Natural Science Foundation of China,Grant/Award Number:52272225。
文摘Solid-state sodium batteries(SSSBs)have been highly prized as a promising alternative to conventional battery systems using organic liquid electrolytes due to their improved safety,higher energy density,and substantial resources and low cost of sodium.Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)solid electrolyte is attracting considerable interest owing to its excellent thermal and chemical stability and favorable compatibility with Na metal anode and high-voltage cathode.However,two main challenges of poor roomtemperature ionic conductivity and high interfacial resistance limit the application of NZSP electrolyte in SSSBs.So far,intensive efforts have been devoted to developing modification strategies to improve the room-temperature ionic conductivity of NZSP.This review aims to provide a comprehensive summary and discussion of some optimization strategies for enhancing the room-temperature ionic conductivity of the NZSP solid electrolyte.These optimization strategies are categorized into foreignion doping or substitution,sintering behavior modulation,and regulation of chemical composition based on precursors,and their optimization mechanisms are also elaborated.Finally,the prospects of NZSP-based solid electrolytes are presented.This review is expected to offer better guidance for designing and developing high-performance NZSP-based solid electrolytes for accelerating the practical application of SSSBs.
基金Project supported by the National Natural Science Foundation of China(Grant No.11872033)the Beijing Natural Science Foundation,China(Grant No.3172017)。
文摘This study investigates the mechanisms of friction-induced vibration under periodic variations in stress distribution using an improved fretting friction model.A fretting friction test system integrated with a total reflection method was developed to analyze interfacial contact behavior under dynamic loading conditions.An improved fretting friction model was established,incorporating three critical nonlinear parameters:the hysteretic friction coefficient,tangential stiffness fluctuations,and stress distribution.Through systematic validation,the model demonstrates high-fidelity replication of experimental steady-state amplitude-frequency responses.Key findings reveal that non-uniform stress distribution governs irregularities in the vibration response,and increased uniformity intensifies stick-slip instabilities.Near the stick-slip transition threshold,distinct vibration anomalies emerge due to the coupled effects of stress heterogeneity,friction hysteresis,and stiffness variations during state transitions.Furthermore,the magnitude of the normal contact force systematically alters the dominant interfacial contact mechanism.The different interfacial contact states at various frequencies lead to distinct steady-state responses.This shift elevates resonance frequencies and amplifies higher-order resonant peaks.The fretting friction model provides a predictive framework for vibration control under dynamic interfacial loading.
基金supported by the National Key R&D Program of China(2021YFB3800300).
文摘High-nickel cathode,LiNi0.8Co0.1Mn0.1O_(2)(NCM811),and sulfide-solid electrolyte are a promising combination for all-solid-state lithium batteries(ASSLBs).However,this combination faces the issue of interfacial instability between the cathode and electrolyte.Given the surface alkalinity of NCM811,we propose a strategy to construct a solid-polymer-electrolyte(SPE)interphase on NCM811 surface by leveraging the surface alkaline residues to nucleophilically initiate the in-situ ring-opening polymerization of cyclic organic molecules.As a proof-of-concept,this study demonstrates that the ring-opening copolymerization of 1,3-dioxolane and maleic anhydride produces a homogeneous,compact,and conformal SPE layer on NCM811 surface to prevent the cathode from contact and reaction with Li6PS5Cl solid-state electrolyte.Consequently,the SPE-modified-NCM811 in ASSLBs exhibits high capacities of 193.5 mA h g^(-1) at 0.2 C,160.9 mA h g^(-1) at 2.0 C and 112.3 mA h g^(-1) at 10 C,and particularly,excellent long-term cycling stabilities over 11000 cycles with a 71.95%capacity retention at 10 C at 25℃,as well as a remained capacity of 117.9 mA h g^(-1) after 8000 cycles at 30 C at 60℃,showing a great application prospect.This study provides a new route for creating electrochemically and structurally stable solid-solid interfaces for ASSLBs.
基金supported by the Fundamental Research Funds for the Central Universities(N2404005)the National Key Research and Development Program of China(2018YFA0702200)+2 种基金Liaoning Revitalization Talents Program(XLYC1801005)the National Natural Science Foundation of China(U23B20118)the Nature Science Foundation of Liaoning Province of China(2022JH25/10100008)。
文摘State constraints in nonlinear systems are commonly pursued by resorting to barrier functions,which enforce constraints over the entire duration of system operation.We propose a universal intermittent state-constrained solution,which not only offers flexibility by activating constraints just during specific time periods of interest to the user,but also successfully accommodates different types of constraint boundaries.The innovative shifting functions are proposed to facilitate seamless transitions between constrained and unconstrained operational phases,resulting in more user-friendly design and implementation.By blending an improved shifting transformation into intermittent constraint design,we construct a universal barrier function upon the constrained states,with which our control strategy removes the limitations on constraint functions and completely obviates the feasibility conditions.Furthermore,a modified fuzzy approximator driven by the prediction error rather than the tracking error achieves decoupling of the control and estimation loops,which not only ensures the estimation performance,but also facilitates proof of stability.Finally,the effectiveness of the proposed scheme is assessed by numerical simulation.
基金financially supported by the National Natural Science Foundation of China(32301962 and 31901127)the China Postdoctoral Science Foundation(2024M752947)+2 种基金the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20232437)the State Key Laboratory of Cotton Bio-breeding and Integrated Utilization Open Fund,China(CB2023C02)the Natural Science Foundation of Henan Province,China(252300420222)。
文摘Legume-based intercropping enhances asymbiotic biological nitrogen fixation(BNF);however,the underlying mechanisms remain unclear,including the roles of soil keystone diazotroph taxa with varying niche breadths.A field experiment was conducted to evaluate soil BNF variations between rhizosphere and bulk soils in peanut/cotton intercropping systems and monocultures.BNF activities were measured by nitrogen fixation rates,nitrogenase activity,and nifH gene abundance.Phylogenetic null models,co-occurrence networks,and niche breadth analysis were applied to investigate the roles of diazotrophic keystone taxa and their ecological niches.Rhizosphere soils exhibited 7.8–125.5%higher BNF potentials than bulk soils,whereas intercropping systems showed 11.6–323.0%increases over monocultures for nitrogen fixation rate,nitrogenase activity,and nifH gene abundance(all P<0.05).Diazotrophic community composition and diversity differed significantly,with Proteobacteria(excluding Alphaproteobacteria)enriched in intercropping and rhizosphere soils,while Cyanobacteria and Firmicutes were less abundant.Deterministic processes,particularly heterogeneous selection,dominated community assembly in the rhizosphere(91.9%)and intercropping soils(86.3%).The co-occurrence networks consistently revealed more complex and interconnected communities in intercropping and rhizosphere soils that were dominated by opportunistic diazotrophs(78.8–85.9%),followed by specialists(10.2–18.5%)and generalists(1.38–3.80%).Keystone taxa,including opportunists such as Azoarcus,Azohydromonas,and Steroidobacter,and generalists like Pseudomonas and Azotobacter,correlated positively with microbial biomass carbon and nitrate nitrogen,contributing to enhanced BNF.Peanut/cotton intercropping enhances BNF by selectively enriching the keystone diazotrophic taxa with varying ecological roles,particularly opportunists and generalists.Such targeted intercropping strategies can optimize BNF,improve soil fertility,and promote sustainable agricultural production.
基金supported by the National Natural Science Foundation of China(Grant No.52192622)the Natural Science Foundation of Sichuan Province,China(Grant No.2025ZNSFSC0371)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(Grant No.SKLGP2022Z018).
文摘Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To understand these complex heat recovery processes,we simulated long-term heat extraction in a surrogate HDR using a true triaxial apparatus.A circulation test was first implemented to analyze the connectivity between different wells.Suitable injection and production wells were then selected for the laboratory heat extraction tests in granite,which lasted 14.5 h.Under variable injection rate conditions,we systematically analyzed the time-varying curves of temperature and flow rate in the production wells and pressure in the injection wells.Our findings showed that the advantage channel was dominant in the flow distribution when several paths existed in EGS.Changes in fracture conductivity are attributed to injection pressure.These included an increase in fracture width and activation of a localized closed area of fracture.These two mechanisms influenced the production temperature,and this is consistent with the field data monitored at the Fenton Hill and Hijiori projects.Fluid leak-off was an important factor affecting the production flow rate.For a fracture with low hydraulic conductivity,a lower injection rate could effectively prevent excessive fluid leak-off.In addition,by comparing injection rates and fluid recovery rates,production wells in different phases or injection modes had different fluid recovery rates even when the injection rates were the same.
基金supported by the National Natural Science Foundation of China(Grant Nos.12205097,12141501,12475117,and 12435006)the National Key Laboratory of Neutron Science and Technology(Grant No.NST202401016)+1 种基金the National Key R&D Program of China(Grant Nos.2024YFA1612600 and 2024YFE0109803)the High-performance Computing Platform of Peking University。
文摘The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice space and the reflection-asymmetric triaxial particle rotor model.It is found that^(229)Th has a ground state with static axial octupole and quadrupole deformations.The occurrence of octupole correlations,driven by the octupole deformation,is analyzed through the evolution of single-particle levels around the Fermi surface.The experimental energy spectrum and the electromagnetic transition probabilities,including B(E2)and B(M1),are reasonably well reproduced.
