Parallelizable Calculation of Observables Values on Analog Quantum Computer

The superiority of hypothetical quantum computers is not due to faster calculations but due to different schemes of calculations running on special hardware. The core of quantum computing follows the way a state of a quantum system is defined when basic things interact with each other. In conventional approach it is implemented through tensor product of qubits. In the geometric algebra formalism simultaneous availability of all the results for non-measured observables is based on the definition of states as points on three-dimensional sphere.

Influence of the Choice of NN Potential Model on γd→τ~0d Observables near η-Threshold

Influence of the choice of the NN potential model governing the deuteron wave function on the observables for coherent π0-photoproduction on the deuteron near η-threshoM is investigated by using a three-body model for the intermediate ηN N system with separable two-body interactions. Results for unpolarized differential cross section and polarization observables are predicted. It is revealed that the choice of the NN potential model has a visible effect on the differential cross section and most of the polarization observables, especially in the photon energy range of 600-800 MeV and extreme backward pion angles. We find that the deviation among results obtained by using different deuteron wave functions is quite large. The use of the CD-Bonn NN potential for deuteron wave function doubles the differential cross section in this kinematic region. Compared with the experimental data from CLAS collaboration for differential cross section, sizeable discrepancies are found.

1-5 Decomposition of the Sensitivity of the Symmetry Energy Observables

To study the nuclear symmetry energy at supra-saturation densities, one generally considers that the observables probe the symmetry energy in the density region of maximal compression. Since the compression of nucleus-nucleus collision is a dynamical process, this point of view is not fully correct due to the effect of the symmetry energy at low densities. To answer which density region that some frequently used symmetry-energy-sensitive observables such as free n/p ratio or π?/π+ ratio probe, we made a study of decomposition of the sensitivity of these symmetryenergy- sensitive observables.

Thermodynamic geometry of the RN-Ad S black hole and non-local observables

This paper studies the thermodynamic geometry of the Reissner–Nordstr?m-anti-de Sitter(RN-AdS)black hole via detection of the non-local observables in the dual field theory,including the entanglement entropy and equal-time two-point correlation function.With the dimensional analysis,we construct the principle of corresponding states of black hole thermodynamics.As a result,our findings can be applied to black holes with different Ad S backgrounds.In this sense,the probe of the thermodynamic geometry of the RN-Ad S black hole though the non-local observables in dual field theory has been confirmed numerically.

Deuteron electromagnetic form factors and tensor polarization observables in the framework of the hard-wall AdS/QCD model

We study the electromagnetic form factors and tensor polarization observables of the deuteron in the framework of the hard-wall AdS/QCD model.We find a profile function for the bulk twistτ=6 vector field,which describes the deuteron on the boundary and fix the infrared boundary cut-off of AdS space in accordance with the ground state mass of the deuteron.We obtain the deuteron charge monopole,quadrupole,and magnetic dipole form factors and tensor polarization observables from the bulk Lagrangians for the deuteron and photon field interactions.We plot the momentum transfer dependence of the form factors and tensor polarization observables and compare our numerical results with those in the soft-wall model and experimental data.

Uncertainty relations for triples of observables and the experimental demonstrations

Uncertainty relations are of profound significance in quantum mechanics and quantum information theory.The well-known Heisenberg-Robertson uncertainty relation presents the constraints on the spread of measurement outcomes caused by the non-commutability of a pair of observables.In this article,we study the uncertainty relation of triple observables to explore the relationship between the standard deviations and the commutators of the observables.We derive and tighten the multiplicative form and weighted summation form uncertainty relations,which are found to be dependent not only on the commutation relations of each pair of the observables but also on a newly defined commutator in terms of all the three observables.We experimentally test the uncertainty relations in a linear optical setup.The experimental and numerical results agree well and show that the uncer-tainty relations derived by us successfully present tight lower bounds in the cases of high-dimensional observables and the cases of mixed states.Our method of deriving the uncertainty relation can be extended to more than three observables.

Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

Magnetopause properties at the dusk magnetospheric flank from global magnetohydrodynamic simulations,the kinetic Vlasov equilibrium,and in situ observations--Potential implications for SMILE

We derived the properties of the terrestrial magnetopause(MP)from two modeling approaches,one global–fluid,the other local–kinetic,and compared the results with data collected in situ by the Magnetospheric Multiscale 2(MMS2)spacecraft.We used global magnetohydrodynamic(MHD)simulations of the Earth’s magnetosphere(publicly available from the NASA-CCMC[National Aeronautics and Space Administration–Community Coordinated Modeling Center])and local Vlasov equilibrium models(based on kinetic models for tangential discontinuities)to extract spatial profiles of the plasma and field variables at the Earth’s MP.The global MHD simulations used initial solar wind conditions extracted from the OMNI database at the time epoch when the MMS2 observes the MP.The kinetic Vlasov model used asymptotic boundary conditions derived from the same in situ MMS measurements upstream or downstream of the MP.The global MHD simulations provide a three-dimensional image of the magnetosphere at the time when the MMS2 crosses the MP.The Vlasov model provides a one-dimensional local view of the MP derived from first principles of kinetic theory.The MMS2 experimental data also serve as a reference for comparing and validating the numerical simulations and modeling.We found that the MP transition layer formed in global MHD simulations was generally localized closer to the Earth(roughly by one Earth radius)from the position of the real MP observed by the MMS.We also found that the global MHD simulations overestimated the thickness of the MP transition by one order of magnitude for three analyzed variables:magnetic field,density,and tangential speed.The MP thickness derived from the local Vlasov equilibrium was consistent with observations for all three of these variables.The overestimation of density in the Vlasov equilibrium was reduced compared with the global MHD solutions.We discuss our results in the context of future SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)campaigns for observing the Earth’s MP.

Path-Following Control With Obstacle Avoidance of Autonomous Surface Vehicles Subject to Actuator Faults

This paper investigates the path-following control problem with obstacle avoidance of autonomous surface vehicles in the presence of actuator faults,uncertainty and external disturbances.Autonomous surface vehicles inevitably suffer from actuator faults in complex sea environments,which may cause existing obstacle avoidance strategies to fail.To reduce the influence of actuator faults,an improved artificial potential function is constructed by introducing the lower bound of actuator efficiency factors.The nonlinear state observer,which only depends on measurable position information of the autonomous surface vehicle,is used to address uncertainties and external disturbances.By using a backstepping technique and adaptive mechanism,a path-following control strategy with obstacle avoidance and fault tolerance is designed which can ensure that the tracking errors converge to a small neighborhood of zero.Compared with existing results,the proposed control strategy has the capability of obstacle avoidance and fault tolerance simultaneously.Finally,the comparison results through simulations are given to verify the effectiveness of the proposed method.

Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China

The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.

A general framework for describing photofission observables of actinides at an average excitation energy below 30 MeV

A reasonable prediction of photofission observables plays a paramount role in understanding the photofission process and guiding various photofission-induced applications,such as short-lived isotope production,nuclear waste disposal,and nuclear safeguards.However,the available experimental data for photofission observables are limited,and the existing models and programs have mainly been developed for neutron-induced fission processes.In this study,a general framework is proposed for characterizing the photofission observables of actinides,including the mass yield distributions(MYD) and isobaric charge distributions(ICD) of fission fragments and the multiplicity and energy distributions of prompt neutrons(n_(p)) and prompt γ rays(γ_(p)).The framework encompasses various systematic neutron models and empirical models considering the Bohr hypothesis and does not rely on the experimental data as input.These models are then validated individually against experimental data at an average excitation energy below 30 MeV,which shows the reliability and robustness of the general framework.Finally,we employ this framework to predict the characteristics of photofission fragments and the emissions of prompt particles for typical actinides including ^(232)Th,^(235,238)U and ^(240)Pu.It is found that the ^(238)U(γ,f) reaction is more suitable for producing neutron-rich nuclei compared to the ^(232)Th(γ,f) reaction.In addition,the average multiplicity number of both n_(p) and yp increases with the average excitation energy.

NADARAYA-WATSON ESTIMATORS FOR REFLECTED STOCHASTIC PROCESSES

We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology.

Characteristics Variation of Atmospheric CO_(2)and CH_(4)in Yongxing Island,South China Sea

Using the observation data in Yongxing Island,South China Sea(SCS)from December 2013 to November 2018,the multiple time scales variation of atmospheric CO_(2)and CH_(4)were analyzed to understand their temporal variation characteristics and controlling factors.The regional-averaged background mole fractions of CO_(2)and CH_(4)both show a single-period sinusoidal variation with a lower value at noon and a higher value in the wee hours.In the seasonal scale,they exhibited a significant seasonal difference with higher values in winter and lower values in summer.In the annual scale,CO_(2)and CH_(4)both show an increasing trend,with an annual growth rate of approximately 3.2 ppm and 12 ppb,respectively.The annual growth rate at this site was higher than the global average.The change in atmospheric CO_(2)and CH_(4)in Yongxing Island was probably caused by the higher emission of the surrounding areas and the airflows driven by monsoon.Hopefully,the long-term and high-resolution greenhouse gases(GHGs)dataset will aid relevent researchers and decision-makers in performing more in-depth studies for GHG sources in order to derive effective strategies.

Experimentally Ruling Out Joint Reality Based on Locality with Device-Independent Steering

As an essential concept to understand the world,whether the real values(or physical realities)of observables are suitable to physical systems beyond the classic has been debated for many decades.Although standard nogo results based on Bell inequalities have ruled out the joint reality of incompatible quantum observables,the possibility of giving simple yet strong arguments to rule out joint reality in any physical system(not necessarily quantum)with weaker assumptions and less observables has been explored and proposed recently.Here,we perform a device-independent experiment on a two-qubit superconducting system to show that the joint reality of two observables is incompatible with locality under the weaker assumption of the reality of observables in a single space-time region(or single qubit).Our results clearly show the violation of certain inequalities derived from both linear and nonlinear criteria.In addition,we study the robustness of the linear and nonlinear criterion against the effect of systematic decoherence.Our demonstration opens up the possibility of delineating classical and non-classical boundaries with simpler nontrivial quantum system.

Unprecedented JWST Observations Contest Cosmological Canons

After more than 18 months of nearly flawless operation,the James Webb Space Telescope(JWST)continues to deliver amazement,making unexpected discoveries,adding new wrinkles to known phenomena,and calling into question long-held theories of how the universe works.“The instruments are working amazingly well,in essentially all cases better than expected,”said Garth Illingworth,professor emeritus of astronomy and astrophysics at the University of California,Santa Cruz(CA,USA),and one of the three originators of the mission over three decades ago.“It has exceeded every one of its performance requirements,which is truly amazing when you think about how complex it is.”That complexity has included three decades of planning,design,and construction,followed by launch and maneuvering 1.5106 km from Earth to its second Lagrange(L2)orbit,unfolding and locking into position the 18 segments of its 6.5 m diameter main mirror,and deploying 8 motors,90 cables,and some 400 pulleys to unfurl its fragile sunshield[1,2].

Sodium Sulfite as a Novel Hypoxia Revulsant Involved in Hypoxic Regulation in Escherichia coli

As a reducing salt,sodium sulfite could deprive oxygen in solution,which could mimic hypoxic stress in Caenorhabditis elegans.In this study,the wildtype Escherichia coli strain MG1655 was used to examine the inhibition of sodium sulfite-induced hypoxia by observing the bacterial growth curves.

A Search for Radio Pulsars in Supernova Remnants Using FAST with One Pulsar Discovered

We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointing was 10 min.We discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+0.1.To judge the association between the pulsar and the SNR,further verification is needed.We also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–0.3.No pulsars were detected in the observations of the other three SNRs.

Distributed Multicircular Circumnavigation Control for UAVs with Desired Angular Spacing

This paper addresses a multicircular circumnavigation control for UAVs with desired angular spacing around a nonstationary target.By defining a coordinated error relative to neighboring angular spacing,under the premise that target information is perfectly accessible by all nodes,a centralized circular enclosing control strategy is derived for multiple UAVs connected by an undirected graph to allow for formation behaviors concerning the moving target.Besides,to avoid the requirement of target’s states being accessible for each UAV,fixed-time distributed observers are introduced to acquire the state estimates in a fixed-time sense,and the upper boundary of settling time can be determined offline irrespective of initial properties,greatly releasing the burdensome communication traffic.Then,with the aid of fixed-time distributed observers,a distributed circular circumnavigation controller is derived to force all UAVs to collaboratively evolve along the preset circles while keeping a desired angular spacing.It is inferred from Lyapunov stability that all errors are demonstrated to be convergent.Simulations are offered to verify the utility of proposed protocol.

Observer-Based Adaptive Robust Precision Motion Control of a Multi-Joint Hydraulic Manipulator

Hydraulic manipulators are usually applied in heavy-load and harsh operation tasks.However,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control performance.Model-based full-state-feedback control is an effective alternative,but the states of a hydraulic manipulator are not always available and reliable in practical applications,particularly the joint angular velocity measurement.Considering that it is not suitable to obtain the velocity signal directly from differentiating of position measurement,the low-pass filtering is commonly used,but it will definitely restrict the closed-loop bandwidth of the whole system.To avoid this problem and realize better control performance,this paper proposes a novel observerbased adaptive robust controller(obARC)for a multi-joint hydraulic manipulator subjected to both parametric uncertainties and the lack of accurate velocity measurement.Specifically,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric uncertainties.Then,the adaptive robust control is developed to compensate for the dynamic uncertainties,and the close-loop system robust stability is theoretically proved under the observation and control errors.Finally,comparative experiments are carried out to show that the designed controller can achieve a performance improvement over the traditional methods,specifically yielding better control accuracy owing to the closed-loop bandwidth breakthrough,which is limited by low-pass filtering in fullstate-feedback control.

Current observation and analysis based on mooring systems in the Andaman Sea

The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite data.Mooring observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 mooring.In the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal winter.In addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency currents.The upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 d.Further analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave packets.Moreover,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation period.In addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.