Design of a high sensitivity and wide range angular rate sensor based on exceptional surface

It is found that when the parity–time symmetry phenomenon is introduced into the resonant optical gyro system and it works near the exceptional point,the sensitivity can in theory be significantly amplified at low angular rate.However,in fact,the exceptional point is easily disturbed by external environmental variables,which means that it depends on harsh experimental environment and strong control ability,so it is difficult to move towards practical application.Here,we propose a new angular rate sensor structure based on exceptional surface,which has the advantages of high sensitivity and high robustness.The system consists of two fiber-optic ring resonators and two optical loop mirrors,and one of the resonators contains a variable ratio coupler and a variable optical attenuator.We theoretically analyze the system response,and the effects of phase and coupling ratio on the system response.Finally,compared with the conventional resonant gyro,the sensitivity of this exceptional surface angular rate sensor can be improved by about 300 times at low speed.In addition,by changing the loss coefficient in the ring resonator,we can achieve a wide range of 600 rad/s.This scheme provides a new approach for the development of ultra-high sensitivity and wide range angular rate sensors in the future.

Exceptional points and quantum dynamics in a non-Hermitian two-qubit system

We study the exceptional-point(EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide the systemparameter space into PT-symmetry unbroken, partially broken and fully broken regimes, each with distinct quantumdynamics characteristics. Particularly, in the partially broken regime, while the PT-symmetry is generally broken in the whole four-dimensional Hilbert space, it is preserved in a two-dimensional subspace such that the quantum dynamics in the subspace are similar to those in the PT-symmetry unbroken regime. In addition, we reveal that the competition between the inter-qubit coupling and the intra-qubit driving gives rise to a complex pattern in the EP variation with system parameters.

Localization Dynamics at the Exceptional Point of Non-Hermitian Creutz Ladder

We propose a quasi-one-dimensional non-Hermitian Creutz ladder with an entirely flat spectrum by introducing alternating gain and loss components while maintaining inversion symmetry.Destructive interference generates a flat spectrum at the exceptional point,where the Creutz ladder maintains coalesced and degenerate eigenvalues with compact localized states distributed in a single plaquette.All excitations are completely confined within the localization area,unaffected by gain and loss.Single-site excitations exhibit nonunitary dynamics with intensities increasing due to level coalescence,while multiple-site excitations may display oscillating or constant intensities at the exceptional point.These results provide insights into the fascinating dynamics of non-Hermitian localization,where level coalescence and degeneracy coexist at the exceptional point.

Reconfigurable metamaterial for asymmetric and symmetric elastic wave absorption based on exceptional point in resonant bandgap

Elastic wave absorption at subwavelength scale is of significance in many engineering applications.Non-Hermitian metamaterials show the ability in high-efficiency wave absorption.However,the single functionality of metamaterials is an important limitation on their practical applications for lack of tunability and reconfigurability.Here,we propose a tunable and reconfigurable non-Hermitian piezoelectric metamaterial bar,in which piezoelectric bars connect with resonant circuits,to achieve asymmetric unidirectional perfect absorption(UPA)and symmetric bidirectional perfect absorption(PA)at low frequencies.The two functions can be arbitrarily switched by rearranging shunted circuits.Based on the reverberation-ray matrix(RRM)method,an approach is provided to achieve UPA by setting an exceptional point(EP)in the coupled resonant bandgap.By using the transfer matrix method(TMM)and the finite element method(FEM),it is observed that a non-Hermitian pseudo-band forms between two resonant bandgaps,and the EP appears at the bottom of the pseudo-band.In addition,the genetic algorithm is used to accurately and efficiently design the shunted circuits for desired low-frequency UPA and PA.The present work may provide new strategies for vibration suppression and guided waves manipulation in wide potential applications.

Nonlinear perturbation of a high-order exceptional point:Skin discrete breathers and the hierarchical power-law scaling

We study the nonlinear perturbation of a high-order exceptional point(EP)of the order equal to the system site number L in a Hatano-Nelson model with unidirectional hopping and Kerr nonlinearity.Notably,we find a class of discrete breathers that aggregate to one boundary,here named as skin discrete breathers(SDBs).The nonlinear spectrum of these SDBs shows a hierarchical power-law scaling near the EP.Specifically,the response of nonlinear energy to the perturbation is given by E_(m)∝Γ~(α_(m)),whereα_(m)=3^(m-1)is the power with m=1,...,L labeling the nonlinear energy bands.This is in sharp contrast to the L-th root of a linear perturbation in general.These SDBs decay in a double-exponential manner,unlike the edge states or skin modes in linear systems,which decay exponentially.Furthermore,these SDBs can survive over the full range of nonlinearity strength and are continuously connected to the self-trapped states in the limit of large nonlinearity.They are also stable,as confirmed by a defined nonlinear fidelity of an adiabatic evolution from the stability analysis.As nonreciprocal nonlinear models may be experimentally realized in various platforms,such as the classical platform of optical waveguides,where Kerr nonlinearity is naturally present,and the quantum platform of optical lattices with Bose-Einstein condensates,our analytical results may inspire further exploration of the interplay between nonlinearity and non-Hermiticity,particularly on high-order EPs,and benchmark the relevant simulations.

Effective interventions to improve domain-specific social, emotional, or academic outcomes for twice-exceptional individuals who are gifted with ADHD as a disability

The demand for effective interventions to improve domain-specific academic outcomes for individuals with special needs at either end of the spectrum has existed for some time.Since the earlier contributions to the literature documenting gifted individuals who were simultaneously exhibiting disabilities,there has been some progress in our understanding.We now know that in individuals with both gifts and disabilities,potentially,either or both of the exceptionalities can obscure the effects of the other,which significantly delays the average time to receive a diagnosis.Such delays in diagnosis detrimentally impact the the form of effective interventions without a diagnosis.The purpose of this paper is t quality of life across various domains because there can be no opportunity to receive help in o determine whether effective interventions exist to improve domain-specific(i.e.,social,emotional,or academic)outcomes for people with both gifts and disabilities.A query was performed using evidence databases TRIP and PDQ for“twice-exceptional,”“Giftedness,”“Disability,”and“intervention.”The four most relevant,freely available studies in English were selected for critique.Despite identifying potential threats to validity among the studies,methodological similarities among them were strong enough to confidently conclude that not only do effective interventions exist for the population of gifted with ADHD,but the outcomes of these interventions may also carry over into other domains resulting in indirect effects.

Digital CEOs in Digital Enterprises:Automating,Augmenting,and Parallel in Metaverse/CPSS/TAOs

BIG models or foundation models are rapidly emerging as a key force in advancing intelligent societies[1]–[3]Their significance stems not only from their exceptional ability to process complex data and simulate advanced cognitive functions,but also from their potential to drive innovation across various industries.

Mode coupling with Fabry-Perot modes in photonic crystal slabs

Fabry–Perot(FP)modes are a class of fundamental resonances in photonic crystal(PhC)slabs.Owing to their low quality factors,FP modes are frequently considered as background fields with their resonance nature being neglected.Nevertheless,FP modes can play important roles in some phenomena,as exemplified by their coupling with guided resonance(GR)modes to achieve bound states in the continuum(BIC).Here,we further demonstrate the genuine resonance mode capability of FP modes PhC slabs.Firstly,we utilize temporal coupled-mode theory to obtain the transmittance of a PhC slab based on the FP modes.Secondly,we construct exceptional points(EPs)in both momentum and parameter spaces through the coupling of FP and GR modes.Furthermore,we identify a Fermi arc connecting two EPs and discuss the far-field polarization topology.This work elucidates that the widespread FPs in PhC slabs can serve as genuine resonant modes,facilitating the realization of desired functionalities through mode coupling.

Majorana tunneling in a one-dimensional wire with non-Hermitian double quantum dots

The combination of non-Hermitian physics and Majorana fermions can give rise to new effects in quantum transport systems. In this work, we investigate the interplay of PT-symmetric complex potentials, Majorana tunneling and interdot tunneling in a non-Hermitian double quantum dots system. It is found that in the weak-coupling regime the Majorana tunneling has pronounced effects on the transport properties of such a system, manifested as splitting of the single peak into three and a reduced 1/4 peak in the transmission function. In the presence of the PT-symmetric complex potentials and interdot tunneling, the 1/4 central peak is robust against them, while the two side peaks are tuned by them. The interdot tunneling only induces asymmetry, instead of moving the conductance peak, due to the robustness of the Majorana modes. There is an exceptional point induced by the union of Majorana tunneling and interdot tunneling. With increased PT-symmetric complex potentials, the two side peaks will move towards each other. When the exceptional point is passed through, these two side peaks will disappear. In the strong-coupling regime, the Majorana fermion induces a 1/4 conductance dip instead of the three-peak structure. PT-symmetric complex potentials induce two conductance dips pinned at the exceptional point. These effects should be accessible in experiments.

Interstitial Doping of SnO_(2) Film with Li for Indium-Free Transparent Conductor

SnO_(2)films exhibit significant potential as cost-effective and high electron mobility substitutes for In_(2)O_(3)films.In this study,Li is incorporated into the interstitial site of the SnO_(2)lattice resulting in an exceptionally low resistivity of 2.028×10^(-3)Ω·cm along with a high carrier concentration of 1.398×10^(20)cm^(-3)and carrier mobility of 22.02 cm^(2)/V·s.

Enhanced Spin–Orbit Torques in Graphene by Pt Adatoms Decoration

Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin–orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(t Pt)/Fe Ni trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/Fe Ni sample without Gr and nearly twice the value of the Gr/Fe Ni sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4 MA/cm^(2)in Gr/Pt/Fe Ni trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories.

Growth of two-inch free-standing heteroepitaxial diamond on Ir/YSZ/Si(001)substrates via laser-patterned templates

As an ultra-wide bandgap semiconductor,diamond garners significant interest due to its exceptional physical properties^([1–3]).These superior characteristics make diamonds highly promising for applications in power electronics^([4]),deep-ultraviolet detectors^([5]),high-energy particle detectors^([6]),and quantum devices based on color centers^([7]).

Quasi-anti-parity–time-symmetric single-resonator micro-optical gyroscope with Kerr nonlinearity

Parity–time(PT) and quasi-anti-parity–time(quasi-APT) symmetric optical gyroscopes have been proposed recently which enhance Sagnac frequency splitting. However, the operation of gyroscopes at the exceptional point(EP) is challenging due to strict fabrication requirements and experimental uncertainties. We propose a new quasi-APT-symmetric micro-optical gyroscope which can be operated at the EP by easily shifting the Kerr nonlinearity. A single resonator is used as the core sensitive component of the quasi-APT-symmetric optical gyroscope to reduce the size, overcome the strict structural requirements and detect small rotation rates. Moreover, the proposed scheme also has an easy readout method for the frequency splitting. As a result, the device achieves a frequency splitting 10~5 times higher than that of a classical resonant optical gyroscope with the Earth's rotation. This proposal paves the way for a new and valuable method for the engineering of micro-optical gyroscopes.

Advanced preparation and application of bimetallic materials in lithium-sulfur batteries:A review

Lithium-sulfur(Li-S)batteries are considered highly promising as next-generation energy storage systems due to high theoretical capacity(2600 Wh kg^(-1))and energy density(1675 mA h g^(-1))as well as the abundant natural reserves,low cost of elemental sulfur,and environmentally friendly properties.However,several challenges impede its commercialization including low conductivity of sulfur itself,the severe“shuttle effect”caused by lithium polysulfides(LiPSs)during charge–discharge processes,volume expansion effects and sluggish reaction kinetics.As a solution,polar metal particles and their compounds have been introduced as the main hosts for sulfur cathode due to their robust catalytic activity and adsorption capability,effectively suppressing the“shuttle effect”of Li PSs.Bimetallic alloys and their compounds with multi-functional properties exhibit remarkable electrochemical performance more readily when compared to single-metal materials.Well-designed bimetallic materials demonstrate larger specific surface areas and richer active sites,enabling simultaneous high adsorption capability and strong catalytic properties.The synergistic effect of the“adsorption-catalysis”sites accelerates the adsorptiondiffusion-conversion process of Li PSs,ultimately achieving a long-lasting Li-S battery.Herein,the latest progress and performance of bimetallic materials in cathodes,separators,and interlayers of Li-S batteries are systematically reviewed.Firstly,the principles and challenges of Li-S batteries are briefly analyzed.Then,various mechanisms for suppressing“shuttle effects”of Li PSs are emphasized at the microscale.Subsequently,the performance parameters of various bimetallic materials are comprehensively summarized,and some improvement strategies are proposed based on these findings.Finally,the future prospects of bimetallic materials are discussed,with the hope of providing profound insights for the rational design and manufacturing of high-performance bimetallic materials for LSBs.

Speech at the Meeting on Cultural Inheritance and Development

Today,we convened a meeting on cultural inheritance and development.Preceding this event,I visited the newly built China National Archives of Publications and Culture and the Chinese Archaeological Museum at the Chinese Academy of History and found them exceptionally insightful.

CULTURE

ORF Vienna Radio Symphony Orchestra Date:April 4,2024 Venue:National Center for the Performing Arts The ORF Vienna Radio Symphony Orchestra defines itself in the Vienna orchestral tradition.Cornelius Meister took over as principal conductor and artistic director in September 2010.The Vienna RSO is known for its exceptional,bold programming.By combining 19th century repertoire with contemporary pieces and rarely performed works of other periods,the programming often places Romantic era classics in unexpected contexts.

On the“News Exception”in Personal Information Protection

Protection of personal information is a significant issue in the construction of legal systems in various countries in the information age.Introducing a balanced approach for protecting personal information is an important goal of basic human rights protection and data legislation.Personal information protection involves comprehensive considerations among various values,and the balanced structure between personal information rights and other rights systems has become the key to legislation on personal information protection.The“news exception”is a prominent example representing the balanced structure of personal information protection.As a societal instrument,news not only pursues commercial value but also advocates freedom of expression and public value.There exists a natural tension between news and personal information protection.The“news exception”of the balanced structure has become a fundamental requirement and important connotation for constructing a system for protecting personal information.The balanced structure of the“news exception”requires a reasonable definition of the concept and purpose of news,and both the self-discipline within the news industry and the judicial intervention are necessary factors.China has preliminarily completed the top-level legislative design of personal information protection through laws such as the Civil Code of the People’s Republic of China(PRC)and the Personal Information Protection Law of the People’s Republic of China.However,the balanced mechanism of the“news exception”has not yet been fully established in China.A“news exception”based on the ideas of balance and the improvement of the institutional system is the fundamental principle for the development of China’s personal information protection system.

Using artificial intelligence to document the hidden RNA virosphere

Current metagenomic tools can fail to identify highly divergent RNA viruses.We developed a deep learning algorithm,termed LucaProt,to discover highly divergent RNA-dependent RNA polymerase(RdRP)sequences in 10,487 metatranscriptomes generated from diverse global ecosystems.LucaProt integrates both sequence and predicted structural information,enabling the accurate detection of RdRP sequences.Using this approach,we identified 161,979 potential RNA virus species and 180 RNA virus supergroups,including many previously poorly studied groups,as well as RNA virus genomes of exceptional length(up to 47,250 nucleotides)and genomic complexity.

探索美食,享受美味

第一部分语言基础(共两节,满分30分)第一节单句填空(共15小题;每小题1分,满分15分)1.At the age of five,he showed(exception)talent as a musician.2.There is convincing evidence that skin cancer is linked exposure to the sun.3.Even though we completely differ each other in character,we are still close friends.

Exceptional family of elements and the solvability of complementarity problems in uniformly smooth and uniformly convex Banach spaces

The notion of “exceptional family of elements (EFE)” plays a very important role in solving complementarity prob- lems. It has been applied in finite dimensional spaces and Hilbert spaces by many authors. In this paper, by using the generalized projection defined by Alber, we extend this notion from Hilbert spaces to uniformly smooth and uniformly convex Banach spaces, and apply this extension to the study of nonlinear complementarity problems in Banach spaces.