Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instr...Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.展开更多
Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants a...Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants and fuzzy controllers.This makes the classic parallel distribution compensation(PDC)control infeasible.To overcome this situation,a novel method for reconstructing the membership functions'grades is proposed,which synchronizes the time scales.Then,the membership function dependent method is adopted to introduce asynchronous errors and detailed membership function information.For the event-triggered control strategy,a series of robust H∞stable conditions in LMI form are derived.Finally,a simulation of a practical system is used to demonstrate the method proposed in this letter can reduce conservatism.展开更多
Permanent dipole moments induced high-order harmonic generation(HHG)signals offer a potential approach to producing elliptically or even circularly polarized X-ray attosecond sources.Previous studies on this topic hav...Permanent dipole moments induced high-order harmonic generation(HHG)signals offer a potential approach to producing elliptically or even circularly polarized X-ray attosecond sources.Previous studies on this topic have mainly focused on diatomic molecules such as CO and HeH.Based on this scheme,significant HHG signals in the direction perpendicular to the molecular axis can be observed in both the high-energy and low-energy regions.However,we found that the high-order harmonics induced by the permanent dipole moments of polyatomic complex molecules involve more intricate physical processes.Using time-dependent density functional theory,we simulated the dynamics of HHG from NH2COOH and NH2COSH interacting with linearly polarized lasers.We found that the harmonic signals in the direction perpendicular to the N-C bond were significantly enhanced in the high-energy photon region.Our analysis indicates that this is due to the complex molecular configuration of NH_(2)COOH and NH_(2)COSH:while the NH_(2) group has C_(2v) symmetry,both COOH and COSH groups lack this symmetry.This structural characteristic results in permanent dipole moments being felt only when electrons return to either COSH or COOH groups,but not to NH_(2) group.Additionally,our results reveal a multi-plateau structure in HHG signal along laser polarization direction,a phenomenon arising from multi-electron and multiorbital effects during interaction between complex molecule and strong laser field.展开更多
A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescenc...A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.展开更多
Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dy...Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dysfunction in the brain.In this study,we enrolled 357 patients with mild intracerebral hemorrhage(ICH)from five hospitals in China and analyzed the relationships between LA and clinical symptom severity at admission,neurological function prognosis at 3 months,and 1-year stroke recurrence.Patients were divided into groups based on Fazekas scale scores:no LA(n=83),mild LA(n=64),moderate LA(n=98)and severe LA(n=112).More severe LA,larger hematoma volume,and higher blood glucose level at admission were associated with more severe neurological deficit.More severe LA,older age and larger hematoma volume were associated with worse neurological function prognosis at 3 months.In addition,moderate-to-severe LA,admission glucose and symptom-free cerebral infarction were associated with 1-year stroke recurrence.These findings suggest that LA severity may be a potential marker of individual ICH vulnerability,which can be characterized by poor tolerance to intracerebral attack or poor recovery ability after ICH.Evaluating LA severity in patients with mild ICH may help neurologists to optimize treatment protocols.This study was approved by the Ethics Committee of Ruijin Hospital Affiliated to Shanghai Jiao Tong University(approval No.12)on March 10,2011.展开更多
In this paper, the definition of approximate XFDs based on value equality is proposed. Two metrics, sup port and strength, are presented for measuring the degree of approximate XFD. A basic algorithm is designed for e...In this paper, the definition of approximate XFDs based on value equality is proposed. Two metrics, sup port and strength, are presented for measuring the degree of approximate XFD. A basic algorithm is designed for extracting minimal set of approximate XFDs, and then two optimized strategies are proposed to improve the performance. Finally, the experimental results show that the optimized algorithms are correct and effective.展开更多
Aviation and aerospace system are typical Phased-Mission Systems(PMSs)featured with varying configuration,phased load condition and cross phase failure correlation.The coupling effect of Functional Dependency(FDEP)and...Aviation and aerospace system are typical Phased-Mission Systems(PMSs)featured with varying configuration,phased load condition and cross phase failure correlation.The coupling effect of Functional Dependency(FDEP)and Physical Dependency(PDEP)has a unique influence on the failure behavior of PMS.In this article,the coupling effect is analyzed,and the degradation of components is modeled with the positive drift wiener process,in which the drift coefficient is related to environmental conditions and operation stress.Finally,failure behavior and system reliability are simulated.An avionics controller is studied as a case,with the degradation time distribution model and simulation algorithm,the coupling effect and dynamical system reliability can be achieved.Results show that this modeling method can describe the coupling effects of FDEP and PDEP and their influence on the failure behavior and reliability of the PMS system.展开更多
According to the analysis of existing complicated functional dependencies constraint, we conclude the conditions of defining functional dependency in XML, and then we introduce the concept of the node value equality. ...According to the analysis of existing complicated functional dependencies constraint, we conclude the conditions of defining functional dependency in XML, and then we introduce the concept of the node value equality. A new path language and a new definition of functional dependencies in XML （XFD） are proposed XFD includes the relative XFD and the absolute XFD, in which absolute key and relative key are the particular cases. We focus on the logical implication and the closure problems, and propose a group of inference rules. Finally, some proofs of the correctness and completeness are given. XFD is powerful on expressing functional dependencies in XML causing data redundancy, and has a complete axiom system.展开更多
Introduction：A key challenge in designing tissue repair strategies is knowing whether and how developmental mechanisms are used for successful repair of mature/adult tissues.Although it is known that developmental co...Introduction：A key challenge in designing tissue repair strategies is knowing whether and how developmental mechanisms are used for successful repair of mature/adult tissues.Although it is known that developmental components are used in repair,it remains mostly unclear which ones are required and whether they act similarly as during development.This issue is further complicated by the fact that it is difficult.展开更多
The study of various oxidation states of chromium with Sargassum <i>sp</i>. is of particular interest since hexavalent chromium </span><span style="font-size:10.0pt;font-family:""&g...The study of various oxidation states of chromium with Sargassum <i>sp</i>. is of particular interest since hexavalent chromium </span><span style="font-size:10.0pt;font-family:"">is </span><span style="font-size:10.0pt;font-family:"">reduced to trivalent chromium in </span><span style="font-size:10.0pt;font-family:"">an </span><span style="font-size:10.0pt;font-family:"">aqueous solution. In this study, a systematic density functional theory (DFT) calculations were performed to study the interactions of transition metal chromium ion with different oxidation states and spin states with the <i>Sar</i></span><i><span style="font-size:10.0pt;font-family:"">gassum sp</span></i><span style="font-size:10.0pt;font-family:"">. decorated with carboxylate</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">(acetate) at the wB97XD/6-311++</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">G(d,p)</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">level of theory. The structures and binding energies of chromium met<span>al</span></span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">carboxylate complexes at various oxidation states and spin states in gas</span><span style="font-size:10.0pt;font-family:""> phase were examined. The coordination strength of Cr(VI) with the acetate <span>ligand was predominantly the strongest compare</span></span><span style="font-size:10.0pt;font-family:"">d</span><span style="font-size:10.0pt;font-family:""> to the other oxidation</span><span style="font-size:10.0pt;font-family:""> states. <span>Vibrational frequency analysis, for the homoleptic monomers of tris</span> <span>[</span><span>Cr<sup>III</sup>(AC)<sub>3</sub>]<sup>0</sup> and </span>[Cr<sup>VI</sup>(AC)<sub>3</sub>]<sup>3+</sup> complexes, illustrate good harmony with the experimental and<span> theoretical calculated frequencies. Using the time</span></span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">dependent DFT</span><span style="font-size:10.0pt;font-family:""> (TD-DFT) at the level of CAM-B3LYP/6-311++G(d,p), the vertical excitation energies were obtained. The stabilization energies derived using the second order perturbation </span><span style="font-size:10.0pt;font-family:"">theory, <i>E</i><sub>ij</sub><sup>(2)</sup>, of NBO analysis confirmed the greater charge transfer for the</span><span style="font-size:10.0pt;font-family:""> observed trends in the metal binding. The calculated binding </span><span style="font-size:10.0pt;font-family:"">energies</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">(ΔE) and interactions energies </span><span style="font-size:10.0pt;font-family:Symbol;">S</span><i><span style="font-size:10.0pt;font-family:"">E</span></i><sub><span style="font-size:10.0pt;font-family:"">ij</span></sub><sup><span style="font-size:10.0pt;font-family:"">(2)</span></sup><span style="font-size:10.0pt;font-family:""> favor</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">the formation of</span><span style="font-size:10.0pt;font-family:""> [Cr<sup>VI</sup>(AC)<sub>3</sub>]<sup>3+</sup> complexes. The findings of this study identify efficient electronic factors as major contributors to the metal binding affinities, with promising possibilities for the design of metal-ligand complexes and sensing of the metal ions.展开更多
Dear Editor,This letter addresses the formation control problem for constrained underactuated autonomous underwater vehicles (AUVs). The feasibility condition of the virtual control law is eliminated by introducing a ...Dear Editor,This letter addresses the formation control problem for constrained underactuated autonomous underwater vehicles (AUVs). The feasibility condition of the virtual control law is eliminated by introducing a nonlinear state dependence function (NSDF) that transforms the state of each AUV in the formation.展开更多
Spin excitations play a fundamental role in understanding magnetic properties of materials,and have significant technological implications for magnonic devices.However,accurately modeling these in transition-metal and...Spin excitations play a fundamental role in understanding magnetic properties of materials,and have significant technological implications for magnonic devices.However,accurately modeling these in transition-metal and rare-earth compounds remains a formidable challenge.Here,we present a fully first-principles approach for calculating spin-wave spectra based on time-dependent(TD)density-functional perturbation theory(DFPT),using nonempirical Hubbard functionals.This approach is implemented in a general noncollinear formulation,enabling the study of magnons in both collinear and noncollinear magnetic systems.Unlike methods that rely on empirical Hubbard U parameters to describe the ground state,and Heisenberg Hamiltonians for describing magnetic excitations,the methodology developed here probes directly the dynamical spin susceptibility(efficiently evaluated with TDDFPT throught the Liouville-Lanczos approach),and treats the linear variation of the Hubbard augmentation(in itself calculated non-empirically)in full at a self-consistent level.Furthermore,the method satisfies the Goldstone condition without requiring empirical rescaling of the exchange-correlation kernel or explicit enforcement of sum rules,in contrast to existing state-of-the-art techniques.We benchmark the novel computational scheme on prototypical transition-metal monoxides NiO and MnO,showing remarkable agreement with experiments and highlighting the fundamental role of these newly implemented Hubbard corrections.The method holds great promise for describing collective spin excitations in complex materials containing localized electronic states.展开更多
First-principles electron dynamics calculations can be applied in the investigation of a wide range of ultrafast phenomena in attosecond physics.They offer unique microscopic insight into light-induced ultrafast pheno...First-principles electron dynamics calculations can be applied in the investigation of a wide range of ultrafast phenomena in attosecond physics.They offer unique microscopic insight into light-induced ultrafast phenomena in both gas and condensed phases of matter,and thus,they are apowerful tool to develop our understanding of the physics of attosecond phenomena.We specifically review techniques employing time-dependent density functional theory(TDDFT)for investigating attosecond and strong-field phenomena.First,we describe this theoretical framework that enables the modeling of perturbative and non-perturbative electron dynamics in materials,including atoms,molecules,and solids.We then discuss its application to attosecond experiments,focusing on the reconstruction of attosecond beating by interference of two-photon transitions(RABBIT)measurements.Wealso briefly review first-principles calculations of optical properties of solids with TDDFT in the linear response regime and their extension to calculations of transient optical properties of solids in non-equilibrium phases,by simulating experimental pump-probe setups.We further demonstrate the application of TDDFT simulation to high-order harmonic generation in solids.First-principles calculations have predictive power,and hence they can be utilized to design future experiments to explore nonequilibrium and nonlinear ultrafast phenomena in matter and characterize and control metastable light-induced quantum states.展开更多
Physical unclonable functions(PUFs),relying extensively on the random spatial distribution of block elements,are promising technology for generating unclonable cryptograph.Herein,we demonstrate time-dependent PUFs(TD-...Physical unclonable functions(PUFs),relying extensively on the random spatial distribution of block elements,are promising technology for generating unclonable cryptograph.Herein,we demonstrate time-dependent PUFs(TD-PUFs)by introducing carbon dots(CDs)with bright and long-lived triplet excitons as block elements.The constructed TD-PUFs evolve into multiple unclonable PUFs over time,effectively breaking the spatial limitation of transitional PUFs and increasing the complexity,making them much more difficult to be attacked.This temporal evolution introduces an additional layer of security,as the dynamic nature of TD-PUFs makes it increasingly challenging for adversaries to predict or replicate their states.We have developed pixel matrix function(PMF)to describe the evolution process of the TD-PUFs,enabling a detailed analysis of the dynamic behavior and unique security features.In addition,we exhibit a TD-PUFs painting(30×40 cm^(2))by an etching technology where the primary structures of the panting undergo a transformation over time,driven by the varying triplet exciton lifetimes of the CDs.The proposed concept of TD-PUFs overcome their spatial limitations and increase the complexity,making the PUF labels more difficulty to be cracked.展开更多
Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE....Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE. Hyperammonaemia and neuroinflammation are two main underlying factors which contribute to the neurological alterations in HE. Both structural and functional impairments are found in the white mater and grey mater involved in HE. Although the investigations into HE pathophysiological mechanism are enormous, the exact pathophysiological causes underlying HE remain controversial. Multimodality magnetic resonance imaging(MRI) plays an important role in helping to understand the pathological process of HE. This paper reviews the up-to-date multimodality MRI methods and predominant findings in HE patients with a highlight ofthe increasingly important role of blood oxygen level dependent functional MRI.展开更多
A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively an...A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively and quantitatively describing the fault diagnosis problem of power transformers. The degree of relation based on the dependent functions was employed to determine the nature and the grade of the faults in a transformer system. And the proposed method was verified with the experimental data. The results show that accuracy rate of the diagnosis method exceeds 90% and two kinds of faults can be detected at the same time.展开更多
For a data cube there are always constraints between dimensions or among attributes in a dimension, such as functional dependencies. We introduce the problem that when there are functional dependencies, how to use the...For a data cube there are always constraints between dimensions or among attributes in a dimension, such as functional dependencies. We introduce the problem that when there are functional dependencies, how to use them to speed up the computation of sparse data cubes. A new algorithm CFD (Computation by Functional Dependencies) is presented to satisfy this demand. CFD determines the order of dimensions by considering cardinalities of dimensions and functional dependencies between dimensions together, thus reduce the number of partitions for such dimensions. CFD also combines partitioning from bottom to up and aggregate computation from top to bottom to speed up the computation further. CFD can efficiently compute a data cube with hierarchies in a dimension from the smallest granularity to the coarsest one. Key words sparse data cube - functional dependency - dimension - partition - CFD CLC number TP 311 Foundation item: Supported by the E-Government Project of the Ministry of Science and Technology of China (2001BA110B01)Biography: Feng Yu-cai (1945-), male, Professor, research direction: database system.展开更多
Starting with the Aalen （1989） version of Cox （1972） ＇regression model＇ we show the method for construction of ＂any＂ joint survival function given marginal survival functions. Basically, however, we restrict o...Starting with the Aalen （1989） version of Cox （1972） ＇regression model＇ we show the method for construction of ＂any＂ joint survival function given marginal survival functions. Basically, however, we restrict ourselves to model positive stochastic dependences only with the general assumption that the underlying two marginal random variables are centered on the set of nonnegative real values. With only these assumptions we obtain nice general characterization of bivariate probability distributions that may play similar role as the copula methodology. Examples of reliability and biomedical applications are given.展开更多
In this paper, based on rough set theory and relational database, the relationship between rough relational database (RRDB) and fuzzy relational database (FRDB) is analyzed systematically from functional dependency, n...In this paper, based on rough set theory and relational database, the relationship between rough relational database (RRDB) and fuzzy relational database (FRDB) is analyzed systematically from functional dependency, normal form and Armstrong axiom. The results show that both fuzzy functional dependency and rough functional dependency are the generalizations of classical functional dependency.Fuzzy normal form is the expansion of classical normal form while rough normal form is an independent system.RRDB and FRDB obey Armstrong axiom to some extent from the point of view of inference rule.展开更多
This paper is concerned with the problem of stability analysis of nonlinear Roesser-type two-dimensional （2D） systems. Firstly, the fuzzy modeling method for the usual one-dimensional （1D） systems is extended to t...This paper is concerned with the problem of stability analysis of nonlinear Roesser-type two-dimensional （2D） systems. Firstly, the fuzzy modeling method for the usual one-dimensional （1D） systems is extended to the 2D ease so that the underlying nonlinear 2D system can be represented by the 2D Takagi Sugeno （TS） fuzzy model, which is convenient for implementing the stability analysis. Secondly, a new kind of fuzzy Lyapunov function, which is a homogeneous polynomially parameter dependent on fuzzy membership functions, is developed to conceive less conser- vative stability conditions for the TS Roesser-type 2D system. In the process of stability analysis, the obtained stability conditions approach exactness in the sense of convergence by applying some novel relaxed techniques. Moreover, the obtained result is formulated in the form of linear matrix inequalities, which can be easily solved via standard numerical software. Finally, a numerical example is also given to demonstrate the effectiveness of the proposed approach.展开更多
基金supported by the Center for Advanced Systems Understanding(CASUS),financed by Germany’s Federal Ministry of Education and Research(BMBF)and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Research Council(ERC)under the European Union’s Horizon 2022 research and innovation programme(Grant Agreement No.101076233,“PREXTREME”)funding from the European Union’s Just Transition Fund(JTF)within the project Röntgenlaser-Optimierung der Laserfusion(ROLF),Contract No.5086999001,co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament.
文摘Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.
基金supported by the National Natural Science Foundation of China(62173218,61833011)International International Cooperation Project of Shanghai Science and Technology Commission(21190780300).
文摘Dear Editor,This letter deals with the controller synthesis problem of networked Takagi-Sugeno(T-S)fuzzy systems.Due to the introduction of network communications,the same premise is no longer shared by fuzzy plants and fuzzy controllers.This makes the classic parallel distribution compensation(PDC)control infeasible.To overcome this situation,a novel method for reconstructing the membership functions'grades is proposed,which synchronizes the time scales.Then,the membership function dependent method is adopted to introduce asynchronous errors and detailed membership function information.For the event-triggered control strategy,a series of robust H∞stable conditions in LMI form are derived.Finally,a simulation of a practical system is used to demonstrate the method proposed in this letter can reduce conservatism.
基金supported by the Fundamental Research Funds for the Central Universities(Grant Nos.GK202207012 and QCYRCXM-2022-241).
文摘Permanent dipole moments induced high-order harmonic generation(HHG)signals offer a potential approach to producing elliptically or even circularly polarized X-ray attosecond sources.Previous studies on this topic have mainly focused on diatomic molecules such as CO and HeH.Based on this scheme,significant HHG signals in the direction perpendicular to the molecular axis can be observed in both the high-energy and low-energy regions.However,we found that the high-order harmonics induced by the permanent dipole moments of polyatomic complex molecules involve more intricate physical processes.Using time-dependent density functional theory,we simulated the dynamics of HHG from NH2COOH and NH2COSH interacting with linearly polarized lasers.We found that the harmonic signals in the direction perpendicular to the N-C bond were significantly enhanced in the high-energy photon region.Our analysis indicates that this is due to the complex molecular configuration of NH_(2)COOH and NH_(2)COSH:while the NH_(2) group has C_(2v) symmetry,both COOH and COSH groups lack this symmetry.This structural characteristic results in permanent dipole moments being felt only when electrons return to either COSH or COOH groups,but not to NH_(2) group.Additionally,our results reveal a multi-plateau structure in HHG signal along laser polarization direction,a phenomenon arising from multi-electron and multiorbital effects during interaction between complex molecule and strong laser field.
文摘A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.
基金supported by the National Natural Science Foundation of China,Nos.81771281(to FXS),81471177(to FXS)the Natural Science Foundation of Shanghai of China,No.20ZR1434200(to YF)。
文摘Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dysfunction in the brain.In this study,we enrolled 357 patients with mild intracerebral hemorrhage(ICH)from five hospitals in China and analyzed the relationships between LA and clinical symptom severity at admission,neurological function prognosis at 3 months,and 1-year stroke recurrence.Patients were divided into groups based on Fazekas scale scores:no LA(n=83),mild LA(n=64),moderate LA(n=98)and severe LA(n=112).More severe LA,larger hematoma volume,and higher blood glucose level at admission were associated with more severe neurological deficit.More severe LA,older age and larger hematoma volume were associated with worse neurological function prognosis at 3 months.In addition,moderate-to-severe LA,admission glucose and symptom-free cerebral infarction were associated with 1-year stroke recurrence.These findings suggest that LA severity may be a potential marker of individual ICH vulnerability,which can be characterized by poor tolerance to intracerebral attack or poor recovery ability after ICH.Evaluating LA severity in patients with mild ICH may help neurologists to optimize treatment protocols.This study was approved by the Ethics Committee of Ruijin Hospital Affiliated to Shanghai Jiao Tong University(approval No.12)on March 10,2011.
基金Supported by the National Natural Science Foun-dation of China (60173051) , Teaching and Research Award Programfor Outstanding Young Teachers in Higher Education Institution ofthe Ministry of Education,the National Research Foundation for theDoctoral Programof Higher Education of China(20030145029) ,andthe Natural Science Foundationfor Doctoral Career Award of LiaoningProvince(20041016)
文摘In this paper, the definition of approximate XFDs based on value equality is proposed. Two metrics, sup port and strength, are presented for measuring the degree of approximate XFD. A basic algorithm is designed for extracting minimal set of approximate XFDs, and then two optimized strategies are proposed to improve the performance. Finally, the experimental results show that the optimized algorithms are correct and effective.
基金funded by the National Natural Science Foundation of China(No.61503014)。
文摘Aviation and aerospace system are typical Phased-Mission Systems(PMSs)featured with varying configuration,phased load condition and cross phase failure correlation.The coupling effect of Functional Dependency(FDEP)and Physical Dependency(PDEP)has a unique influence on the failure behavior of PMS.In this article,the coupling effect is analyzed,and the degradation of components is modeled with the positive drift wiener process,in which the drift coefficient is related to environmental conditions and operation stress.Finally,failure behavior and system reliability are simulated.An avionics controller is studied as a case,with the degradation time distribution model and simulation algorithm,the coupling effect and dynamical system reliability can be achieved.Results show that this modeling method can describe the coupling effects of FDEP and PDEP and their influence on the failure behavior and reliability of the PMS system.
基金Supported by the National Natural Science Foundation of China (60573089)the National High Technology Research and Development Program of China (2006AA09Z139)
文摘According to the analysis of existing complicated functional dependencies constraint, we conclude the conditions of defining functional dependency in XML, and then we introduce the concept of the node value equality. A new path language and a new definition of functional dependencies in XML （XFD） are proposed XFD includes the relative XFD and the absolute XFD, in which absolute key and relative key are the particular cases. We focus on the logical implication and the closure problems, and propose a group of inference rules. Finally, some proofs of the correctness and completeness are given. XFD is powerful on expressing functional dependencies in XML causing data redundancy, and has a complete axiom system.
基金supported by grants from the National Institutes of Health(P20GM103440)the University of Nevada,Las Vegas(a Faculty Opportunity Award and a doctoral dissertation graduate assistantship)to KAST
文摘Introduction：A key challenge in designing tissue repair strategies is knowing whether and how developmental mechanisms are used for successful repair of mature/adult tissues.Although it is known that developmental components are used in repair,it remains mostly unclear which ones are required and whether they act similarly as during development.This issue is further complicated by the fact that it is difficult.
文摘The study of various oxidation states of chromium with Sargassum <i>sp</i>. is of particular interest since hexavalent chromium </span><span style="font-size:10.0pt;font-family:"">is </span><span style="font-size:10.0pt;font-family:"">reduced to trivalent chromium in </span><span style="font-size:10.0pt;font-family:"">an </span><span style="font-size:10.0pt;font-family:"">aqueous solution. In this study, a systematic density functional theory (DFT) calculations were performed to study the interactions of transition metal chromium ion with different oxidation states and spin states with the <i>Sar</i></span><i><span style="font-size:10.0pt;font-family:"">gassum sp</span></i><span style="font-size:10.0pt;font-family:"">. decorated with carboxylate</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">(acetate) at the wB97XD/6-311++</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">G(d,p)</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">level of theory. The structures and binding energies of chromium met<span>al</span></span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">carboxylate complexes at various oxidation states and spin states in gas</span><span style="font-size:10.0pt;font-family:""> phase were examined. The coordination strength of Cr(VI) with the acetate <span>ligand was predominantly the strongest compare</span></span><span style="font-size:10.0pt;font-family:"">d</span><span style="font-size:10.0pt;font-family:""> to the other oxidation</span><span style="font-size:10.0pt;font-family:""> states. <span>Vibrational frequency analysis, for the homoleptic monomers of tris</span> <span>[</span><span>Cr<sup>III</sup>(AC)<sub>3</sub>]<sup>0</sup> and </span>[Cr<sup>VI</sup>(AC)<sub>3</sub>]<sup>3+</sup> complexes, illustrate good harmony with the experimental and<span> theoretical calculated frequencies. Using the time</span></span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">dependent DFT</span><span style="font-size:10.0pt;font-family:""> (TD-DFT) at the level of CAM-B3LYP/6-311++G(d,p), the vertical excitation energies were obtained. The stabilization energies derived using the second order perturbation </span><span style="font-size:10.0pt;font-family:"">theory, <i>E</i><sub>ij</sub><sup>(2)</sup>, of NBO analysis confirmed the greater charge transfer for the</span><span style="font-size:10.0pt;font-family:""> observed trends in the metal binding. The calculated binding </span><span style="font-size:10.0pt;font-family:"">energies</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">(ΔE) and interactions energies </span><span style="font-size:10.0pt;font-family:Symbol;">S</span><i><span style="font-size:10.0pt;font-family:"">E</span></i><sub><span style="font-size:10.0pt;font-family:"">ij</span></sub><sup><span style="font-size:10.0pt;font-family:"">(2)</span></sup><span style="font-size:10.0pt;font-family:""> favor</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">the formation of</span><span style="font-size:10.0pt;font-family:""> [Cr<sup>VI</sup>(AC)<sub>3</sub>]<sup>3+</sup> complexes. The findings of this study identify efficient electronic factors as major contributors to the metal binding affinities, with promising possibilities for the design of metal-ligand complexes and sensing of the metal ions.
基金supported by the National Natural Science Foundation of China(62073094)the Fundamental Research Funds for the Central Universities(3072024GH0404)
文摘Dear Editor,This letter addresses the formation control problem for constrained underactuated autonomous underwater vehicles (AUVs). The feasibility condition of the virtual control law is eliminated by introducing a nonlinear state dependence function (NSDF) that transforms the state of each AUV in the formation.
基金support by the NCCR MARVEL,a National Centre of Competence in Research,funded by the Swiss National Science Foundation(Grant number 205602)the Fellowship from the EPFL QSE Center“Many-body neural simulations of quantum materials”(Grant number 10060)supported by a grant from the Swiss National Supercomputing Centre(CSCS)under project ID s1073 and mr33(Piz Daint).
文摘Spin excitations play a fundamental role in understanding magnetic properties of materials,and have significant technological implications for magnonic devices.However,accurately modeling these in transition-metal and rare-earth compounds remains a formidable challenge.Here,we present a fully first-principles approach for calculating spin-wave spectra based on time-dependent(TD)density-functional perturbation theory(DFPT),using nonempirical Hubbard functionals.This approach is implemented in a general noncollinear formulation,enabling the study of magnons in both collinear and noncollinear magnetic systems.Unlike methods that rely on empirical Hubbard U parameters to describe the ground state,and Heisenberg Hamiltonians for describing magnetic excitations,the methodology developed here probes directly the dynamical spin susceptibility(efficiently evaluated with TDDFPT throught the Liouville-Lanczos approach),and treats the linear variation of the Hubbard augmentation(in itself calculated non-empirically)in full at a self-consistent level.Furthermore,the method satisfies the Goldstone condition without requiring empirical rescaling of the exchange-correlation kernel or explicit enforcement of sum rules,in contrast to existing state-of-the-art techniques.We benchmark the novel computational scheme on prototypical transition-metal monoxides NiO and MnO,showing remarkable agreement with experiments and highlighting the fundamental role of these newly implemented Hubbard corrections.The method holds great promise for describing collective spin excitations in complex materials containing localized electronic states.
基金supported by JSPS KAKENHI Grant Numbers JP20K14382 and JP21H01842the Cluster of Excellence 'CUI: Advanced Imaging of Matter'- EXC 2056 - project ID 390715994+5 种基金SFB-925 "Light induced dynamics and control of correlated quantum systems" – project 170620586 of the Deutsche Forschungsgemeinschaft (DFG)the Max Planck-New York City Center for Non-Equilibrium Quantum PhenomenaThis work was also supported by MEXT Promotion of Development of a Joint Usage/ Research System Project: Coalition of Universities for Research Excellence Program (CURE) Grant Number JPMXP1323015474We also acknowledge support from the Marie Sk{\l}odowska- Curie Doctoral Network TIMES, grant No. 101118915, and SPARKLE grant No. 101169225the Italian Ministry of University and Research (MUR) under the PRIN 2022 Grant No 2022PX279E_003Next Generation EUPartenariato Esteso NQSTI - Spoke 2 (THENCE-PE00000023). The Flatiron Institute is a division of the Simons Foundation. This work used computational resources of the HPC systems at the Max Planck Computing and Data Facility (MPCDF), and the Fujitsu PRIMERGY CX400M1/CX2550M5 (Oakbridge-CX) at the Information Technology Center, the University of Tokyo through the HPCI System Research Project (Project ID:hp220112).
文摘First-principles electron dynamics calculations can be applied in the investigation of a wide range of ultrafast phenomena in attosecond physics.They offer unique microscopic insight into light-induced ultrafast phenomena in both gas and condensed phases of matter,and thus,they are apowerful tool to develop our understanding of the physics of attosecond phenomena.We specifically review techniques employing time-dependent density functional theory(TDDFT)for investigating attosecond and strong-field phenomena.First,we describe this theoretical framework that enables the modeling of perturbative and non-perturbative electron dynamics in materials,including atoms,molecules,and solids.We then discuss its application to attosecond experiments,focusing on the reconstruction of attosecond beating by interference of two-photon transitions(RABBIT)measurements.Wealso briefly review first-principles calculations of optical properties of solids with TDDFT in the linear response regime and their extension to calculations of transient optical properties of solids in non-equilibrium phases,by simulating experimental pump-probe setups.We further demonstrate the application of TDDFT simulation to high-order harmonic generation in solids.First-principles calculations have predictive power,and hence they can be utilized to design future experiments to explore nonequilibrium and nonlinear ultrafast phenomena in matter and characterize and control metastable light-induced quantum states.
基金supported by the National Natural Science Foundation of China(Grant Nos.62075198,11974317,12274378)China Postdoctoral Science Foundation under Grant(Grant No.BX20240337)Key Research and Promotion Projects in Henan Province(Grant No.252102231055).
文摘Physical unclonable functions(PUFs),relying extensively on the random spatial distribution of block elements,are promising technology for generating unclonable cryptograph.Herein,we demonstrate time-dependent PUFs(TD-PUFs)by introducing carbon dots(CDs)with bright and long-lived triplet excitons as block elements.The constructed TD-PUFs evolve into multiple unclonable PUFs over time,effectively breaking the spatial limitation of transitional PUFs and increasing the complexity,making them much more difficult to be attacked.This temporal evolution introduces an additional layer of security,as the dynamic nature of TD-PUFs makes it increasingly challenging for adversaries to predict or replicate their states.We have developed pixel matrix function(PMF)to describe the evolution process of the TD-PUFs,enabling a detailed analysis of the dynamic behavior and unique security features.In addition,we exhibit a TD-PUFs painting(30×40 cm^(2))by an etching technology where the primary structures of the panting undergo a transformation over time,driven by the varying triplet exciton lifetimes of the CDs.The proposed concept of TD-PUFs overcome their spatial limitations and increase the complexity,making the PUF labels more difficulty to be cracked.
基金Supported by Grants from National Natural Science Foundation of China,Nos.30700194,81171313,81322020 and 81230032(to Zhang LJ)Program for New Century Excellent Talents in University,No.NCET-12-0260(to Zhang LJ)
文摘Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE. Hyperammonaemia and neuroinflammation are two main underlying factors which contribute to the neurological alterations in HE. Both structural and functional impairments are found in the white mater and grey mater involved in HE. Although the investigations into HE pathophysiological mechanism are enormous, the exact pathophysiological causes underlying HE remain controversial. Multimodality magnetic resonance imaging(MRI) plays an important role in helping to understand the pathological process of HE. This paper reviews the up-to-date multimodality MRI methods and predominant findings in HE patients with a highlight ofthe increasingly important role of blood oxygen level dependent functional MRI.
文摘A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively and quantitatively describing the fault diagnosis problem of power transformers. The degree of relation based on the dependent functions was employed to determine the nature and the grade of the faults in a transformer system. And the proposed method was verified with the experimental data. The results show that accuracy rate of the diagnosis method exceeds 90% and two kinds of faults can be detected at the same time.
文摘For a data cube there are always constraints between dimensions or among attributes in a dimension, such as functional dependencies. We introduce the problem that when there are functional dependencies, how to use them to speed up the computation of sparse data cubes. A new algorithm CFD (Computation by Functional Dependencies) is presented to satisfy this demand. CFD determines the order of dimensions by considering cardinalities of dimensions and functional dependencies between dimensions together, thus reduce the number of partitions for such dimensions. CFD also combines partitioning from bottom to up and aggregate computation from top to bottom to speed up the computation further. CFD can efficiently compute a data cube with hierarchies in a dimension from the smallest granularity to the coarsest one. Key words sparse data cube - functional dependency - dimension - partition - CFD CLC number TP 311 Foundation item: Supported by the E-Government Project of the Ministry of Science and Technology of China (2001BA110B01)Biography: Feng Yu-cai (1945-), male, Professor, research direction: database system.
文摘Starting with the Aalen （1989） version of Cox （1972） ＇regression model＇ we show the method for construction of ＂any＂ joint survival function given marginal survival functions. Basically, however, we restrict ourselves to model positive stochastic dependences only with the general assumption that the underlying two marginal random variables are centered on the set of nonnegative real values. With only these assumptions we obtain nice general characterization of bivariate probability distributions that may play similar role as the copula methodology. Examples of reliability and biomedical applications are given.
文摘In this paper, based on rough set theory and relational database, the relationship between rough relational database (RRDB) and fuzzy relational database (FRDB) is analyzed systematically from functional dependency, normal form and Armstrong axiom. The results show that both fuzzy functional dependency and rough functional dependency are the generalizations of classical functional dependency.Fuzzy normal form is the expansion of classical normal form while rough normal form is an independent system.RRDB and FRDB obey Armstrong axiom to some extent from the point of view of inference rule.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60972164,60904101,and 61273029)the Key Project of Chinese Ministry of Education(Grant No.212033)+3 种基金the Key Technologies R & D Program of Liaoning Province (Grant No.2011224006)the Program for Liaoning Innovative Research Team in University(Grant No.LT2011019)the Program for Liaoning Excellent Talents in University(Grant No.LJQ2011137)the Science and Technology Program of Shenyang (Grant No.F11-264-1-70)
文摘This paper is concerned with the problem of stability analysis of nonlinear Roesser-type two-dimensional （2D） systems. Firstly, the fuzzy modeling method for the usual one-dimensional （1D） systems is extended to the 2D ease so that the underlying nonlinear 2D system can be represented by the 2D Takagi Sugeno （TS） fuzzy model, which is convenient for implementing the stability analysis. Secondly, a new kind of fuzzy Lyapunov function, which is a homogeneous polynomially parameter dependent on fuzzy membership functions, is developed to conceive less conser- vative stability conditions for the TS Roesser-type 2D system. In the process of stability analysis, the obtained stability conditions approach exactness in the sense of convergence by applying some novel relaxed techniques. Moreover, the obtained result is formulated in the form of linear matrix inequalities, which can be easily solved via standard numerical software. Finally, a numerical example is also given to demonstrate the effectiveness of the proposed approach.
