Nonzero Number Research Articles

Mode structure symmetry breaking of reversed shear Alfvén eigenmodes and its impact on the generation of parallel velocity asymmetries in energetic particle distribution

In this work, the gyrokinetic eigenvalue code LIGKA, the drift-kinetic/MHD hybrid code HMGC and the gyrokinetic full-f code TRIMEG-GKX are employed to study the mode structure details of reversed shear Alfvén eigenmodes (RSAEs). Using the parameters from an ASDEX-Upgrade plasma, a benchmark with the three different physical models for RSAE without and with energetic particles (EPs) is carried out. Reasonable agreement has been found for the mode frequency and the growth rate. Mode structure symmetry breaking (MSSB) is observed when EPs are included, due to the EPs’ non-perturbative effects. It is found that the MSSB properties are featured by a finite radial wave phase velocity, and the linear mode structure can be well described by an analytical complex Gaussian expression with complex parameters σ and s 0, where s is the normalized radial coordinate. The mode structure is distorted in opposite manners when the EP drive shifted from one side of to the other side, and specifically, a non-zero average radial wave number 〈k s 〉 with opposite signs is generated. The initial EP density profiles and the corresponding mode structures have been used as the input of HAGIS code to study the EP transport. The parallel velocity of EPs is generated in opposite directions, due to different values of the average radial wave number 〈k s 〉, corresponding to different initial EP density profiles with EP drive shifted away from the .

On construction of lightweight MDS matrices

MDS matrices are widely used in block ciphers. Constructing lightweight MDS matrices is one of the research focuses of lightweight cryptography. In this paper, we define a new operation called the Copy operation by using registers. It is a generalization of Type 3 elementary operations (add a row to another one multiplied by a nonzero number). It is shown that any nonsingular matrix can be obtained by Copy operations and Multiplication operations from the identity matrix $ I $ (a Copy Block Implementation of the matrix). Thus we introduce a new metric called gw-xor using Copy Block Implementations to construct lightweight MDS matrices with respect to low xor gates. Compared with sw-xor, the gw-xor count is a better approximation of the optimal implementation cost, and in particular it may be a better approximation of the optimal implementation cost than s-xor. By searching the potential paths of Copy operations that can obtain formal MDS matrices (i.e., matrices with indeterminate elements and each determinant of square submatrix of any order is a nonzero polynomial in these indeterminates), we find 52 classes $ 16\times 16 $ and $ 32\times 32 $ binary MDS matrices with 35 and 67 xor gates respectively, which are the best known results. Furthermore, by considering the depth of MDS matrices, we find more $ 4\times4 $ MDS matrices over $ \mathbb{F}_{2^n} $ with the lowest xor gates at depths 3, 4, 5.

On the coprimeness relation from the viewpoint of monadic second-order logic

Let $\mathfrak{C}$ denote the structure of the natural numbers with the coprimeness relation. We prove that for each non-zero natural number $n$, if a $\Pi^1_n$-set of natural numbers is closed under automorphisms of $\mathfrak{C}$, then it is definable in $\mathfrak{C}$ by a monadic $\Pi^1_n$-formula of the signature of $\mathfrak{C}$ having exactly $n$ set quantifiers. On the other hand, we observe that even a much weaker version of this property fails for certain expansions of $\mathfrak{C}$.

Helical Magnetogenesis with Reheating Phase from Higher Curvature Coupling and Baryogenesis

We investigate the generation of helical magnetic fields and address the baryon asymmetry of the universe from an inflationary magnetogenesis scenario, in which the conformal and parity symmetries of the electromagnetic field are broken through its coupling the Ricci scalar and the Gauss-Bonnet invariant via the dual field tensor, so that the generated magnetic field can have a helical nature. It is demonstrated that if a reheating phase with non-zero e-fold numbers following inflation is taken into account, the energy density of the magnetic fields as well as their helicity spectrum evolve differently compared to those for the instantaneous reheating case. As a result, it is shown that in presence of the reheating phase, both the field strength of the generated magnetic fields and the resultant baryon asymmetry of the universe can be compatible with the observations. Furthermore, we find a viable constraint on the reheating equation of state parameter $\omega_\mathrm{eff}$ from the data of the cosmic microwave background radiation as $0.284 \lesssim \omega_\mathrm{eff} \lesssim 0.2975$, which is consistent with a negligible Schwinger backreaction.

Vibrations of a Cylindrical Sandwich Shell with a Honeycomb Core Made Using FDM technology

Presented is a model of the dynamic deformation of a three-layer cylindrical shell with a honeycomb core, manufactured by fused deposition modeling (FDM), and skins reinforced with oriented carbon nano-tubes (CNT). A ULTEM 9085 thermoplastic-based honeycomb core is considered. To analyze the stress-strain state of the honeycomb core, a finite element homogenization procedure was used. As a result of this procedure, the dynamic response of the honeycomb core is modeled by a homogeneous orthotropic material, whose mechanical properties correspond to those of the core. The proposed model is based on the high-order theory, extended for the analysis of sandwich structures. The skin displacement projections are expanded along the transverse coordinate up to quadratic terms. The honeycomb core displacement projections are expanded along the transverse coordinate up to cubic terms. To ensure the integrity of the structure, shell displacement continuity conditions at the junction of the layers are used. The investigation of linear vibrations of the shell is carried out using the Rayleigh-Ritz method. For its application, the potential and kinetic energies of the structure are derived. Considered are the natural frequencies and modes of vibrations of a one-side clamped cylindrical sandwich shell. The dependence of the forms and frequencies of vibrations on the honeycomb core thickness and the direction of reinforcement of the shell skins have been investigated. It was found that the eigenforms of a sandwich shell are characterized by a smaller number of waves in the circumferential direction, as well as a much earlier appearance of axisymmetric forms. This means that when analyzing the resonant vibrations of a sandwich shell, it is necessary to take into account axisymmetric shapes. Changing the direction of reinforcement of the skins with CNTs makes it possible to significantly influence the frequencies of the natural vibrations of the shell, which are characterized by a nonzero number of waves in the circumferential direction. It was found that this parameter does not affect the frequencies of the axisymmetric shapes of the shell under consideration.

The Klein–Gordon equation with equal scalar and vector Bargmann potentials in [formula omitted] dimensions

Using an improved Greene-Aldrich approximation scheme to handle the centrifugal potential, we solve the D-dimensional Klein–Gordon equation with equal scalar and vector Bargmann potentials with a non-zero angular momentum number. The equation giving the bound-state energy eigenvalues as well as the corresponding normalized radial wave functions are obtained. The particular cases of Hultén and Yukawa potentials are also discussed. A lower-bound for the energy levels is obtained and their behaviour with the parameters of the Bargmann potential is analysed.

Quantum Dark Solitons in the 1D Bose Gas: From Single to Double Dark-Solitons

We study quantum double dark-solitons, which give pairs of notches in the density profiles, by constructing corresponding quantum states in the Lieb–Liniger model for the one-dimensional Bose gas. Here, we expect that the Gross–Pitaevskii (GP) equation should play a central role in the long distance mean-field behavior of the 1D Bose gas. We first introduce novel quantum states of a single dark soliton with a nonzero winding number. We show them by exactly evaluating not only the density profile but also the profiles of the square amplitude and phase of the matrix element of the field operator between the N-particle and (N−1)-particle states. For elliptic double dark-solitons, the density and phase profiles of the corresponding states almost perfectly agree with those of the classical solutions, respectively, in the weak coupling regime. We then show that the scheme of the mean-field product state is quite effective for the quantum states of double dark solitons. Assigning the ideal Gaussian weights to a sum of the excited states with two particle-hole excitations, we obtain double dark-solitons of distinct narrow notches with different depths. We suggest that the mean-field product state should be well approximated by the ideal Gaussian weighted sum of the low excited states with a pair of particle-hole excitations. The results of double dark-solitons should be fundamental and useful for constructing quantum multiple dark-solitons.

Epitaxial Growth of Ultraflat Bismuthene with Large Topological Band Inversion Enabled by Substrate-Orbital-Filtering Effect.

Quantum spin Hall (QSH) systems hold promises of low-power-consuming spintronic devices, yet their practical applications are extremely impeded by the small energy gaps. Fabricating QSH materials with large gaps, especially under the guidance of design principles, is essential for both scientific research and practical applications. Here, we demonstrate that large on-site atomic spin-orbit coupling can be directly exploited via the intriguing substrate-orbital-filtering effect to generate large-gap QSH systems and experimentally realized on the epitaxially synthesized ultraflat bismuthene on Ag(111). Theoretical calculations reveal that the underlying substrate selectively filters Bi pz orbitals away from the Fermi level, leading pxy orbitals with nonzero magnetic quantum numbers, resulting in large topological gap of ∼1 eV at the K point. The corresponding topological edge states are identified through scanning tunneling spectroscopy combined with density functional theory calculations. Our findings provide general strategies to design large-gap QSH systems and further explore their topology-related physics.

Dynamic formation of quasicondensate and spontaneous vortices in a strongly interacting Fermi gas

We report an experimental study of quench dynamics across the superfluid transition temperature $T_c$ in a strongly interacting Fermi gas by ramping down the trapping potential. The nonzero quasi-condensate number $N_0$ at temperature significantly above $T_c$ in the unitary and the BEC regimes reveals the pseudogap physics. Below $T_c$, a rapid growth of $N_0$ is accompanied by spontaneous generation of tens of vortices. We observe a power law scaling of the vortex density versus the quasi-condensate formation time, consistent with the Kibble-Zurek theory. Our work provides an example of studying emerged many-body physics by quench dynamics and paves the way for studying the quantum turbulence in a strongly interacting Fermi gas.

Electron-LO-phonon intrasubband scattering rates in a hollow cylinder under the influence of a uniform axial applied magnetic field

Scattering rates arising from the interactions of electrons with bulk longitudinal optical (LO) phonon modes in a hollow cylinder are calculated as functions of the inner radius and the uniform axial applied magnetic field. Now, the specific nature of electron-phonon interactions mainly depends on the character of the energy spectrum of electrons. As is well known, in cylindrical quantum wires, the application of a parallel magnetic field lifts the double degeneracy of the non-zero azimuthal quantum number states; \(m \not = 0\); irrespective of all electron’s radial quantum number l states. In fact, this Zeeman splitting is such that the \(m < 0\) electron’s energy subbands initially decrease with the increase of the parallel applied magnetic field. In a solid cylinder, the lowest-order; {\(l = 1;\,m = 0\)} subband is always the ground state. In a hollow cylinder, however, as the axial applied magnetic field is increased, the electron’s energy subbands take turns at becoming the ground state; following the sequence \(\lbrace m=0,-1,-2...~ -N\rbrace\) of azimuthal quantum numbers. Furthermore, in a hollow cylinder, in general, the electron’s energy separations between any two subbands are less than the LO phonon energy except for exceptionally high magnetic fields, and some highest-order quantum number states. In view of this, the discussion of the energy relaxation here is focused mainly on intrasubband scattering of electrons and only within the lowest-order {\(l = 1;\,m = 0\)} electron’s energy subband. The intrasubband scattering rates are found to be characterized by shallow minima in their variations with the inner radius, again, for a fixed outer radius. This feature is a consequence of a balance between two seemingly conflicting effects of the electron’s confinement by the inner and outer walls of the hollow cylinder. First; increased confinement of the charge carriers generally leads to the enhancement of the rates. Second; the presence of a hole in a hollow cylinder leads to a significant suppression of the scattering rates. The intrasubband scattering rates also show a somewhat parabolic increase in their variations with the applied magnetic field; an increase which is more pronounced in a relatively thick hollow cylinder.

Integrated Transcriptomics and Proteomics Identifies Therapeutic Targets in Pediatric Acute Myeloid Leukemia

Acute myeloid leukemia (AML) remains a therapeutic challenge with high mortality rates despite intensive and myeloablative therapies. While immunotherapies targeting CD19 have yielded remarkable outcomes in acute lymphoblastic leukemia, identifying similar antigen therapeutic targets in AML remains a challenge due to inherent heterogeneity associated with AML and overlapping immunophenotypes with normal hematopoietic stem and myeloid cell populations. Transcriptional heterogeneity within pediatric AML has primarily been linked to underlying fusion. Therefore, we integrated large transcriptomics and proteomics datasets from AML and normal tissues to identify potential targets expressed in leukemias, but not in normal bone marrow or other normal tissue types.To identify candidate therapeutic targets in pediatric AML, we leveraged transcriptome sequencing data from bone marrow aspirates or peripheral blood collected from 1,481 children, adolescents, and young adults with AML at the time of diagnosis. Patients were enrolled on one of four Children's Oncology Group trials spanning the past three decades: CCG-2961, AAML03P1, AAML0531, and AAML1031. We also leveraged transcriptome sequencing from normal bone marrow (NBM) and normal CD34+ hematopoietic stem and progenitor cells (HSPCs) in order to exclude targets that are highly expressed during normal hematopoiesis. Finally, we performed additional filtering based on proteomic databases to exclude targets that lack membrane localization (Human Protein Atlas, UniProt, and Ensembl) or that are highly expressed on normal tissue types (Human Proteome Map, Human Protein Atlas, and Proteomics DB databases) (Figure 1A).First, we computed the log expression ratio between AMLs and NBM/HSCPs for all protein coding genes. We next selected genes expressed greater than a threshold of two standard deviations above the mean in 50% or more of AMLs (Figure 1B). Additionally, we further selected genes on the basis of differential gene expression and absolute expression thresholds. This analysis was repeated for our entire pediatric AML cohort and the following AML subtypes: RUNX1-RUNX1T1, CBFB-MYH11, KMT2A-MLLT3, KMT2A-MLLT10, KMT2A-MLLT4, KMT2A-ELL, KMT2A-MLLT1, KMT2A-MLLT11, NUP98-NSD1, NUP98-KDM5A, and CBFA2T3-GLIS2. Candidate therapeutic targets were filtered based on membrane localization and normal tissue expression using the aforementioned proteomics databases (Figure 1C and 1D). Based on this algorithm, we identified a nonzero number of candidate therapeutic targets for each of our pediatric AML subtypes (Figure 1D). Intriguingly, we found no overlap between targets identified in our pediatric, adolescent, and young adult cohort and a previous similar analysis performed in AMLs diagnosed in older patients (PMID 29017060).This study demonstrates that by combining our large transcriptomics dataset with pre-existing proteomics datasets, we are able to identify a collection of candidate therapeutic targets in pediatric AML. Importantly, zero targets were identified that were inclusive to all pediatric AMLs within our cohort, which underscores the transcriptional heterogeneity that our group and others have previously identified in pediatric AML. Future preclinical and clinical studies will need to account for this heterogeneity by prioritizing targets on the basis of underlying molecular alteration. Our study comprises a platform and dataset of candidate targets for further functional validation and/or immunotherapy targeting studies in pediatric AML. [Display omitted] DisclosuresShaw: T-Cell and/or Gene Therapy for Cancer: Patents & Royalties.

Gravitational collision efficiencies of small viscous drops at finite Stokes numbers and low Reynolds numbers

Collision efficiencies are calculated for two sedimenting spherical drops of different radii with internal circulation under conditions such that drop inertia can be significant while the surrounding fluid inertia remains negligible. A trajectory analysis is employed with exact methods for determining the hydrodynamic forces. When the Reynolds number is small, fluid inertia is negligible, and the hydrodynamic forces are linear functions of the velocities of the drops. However, at nonzero Stokes numbers, drop inertia must be taken into account, and the hydrodynamic forces do not balance the applied forces. For drops in close approach, lubrication forces, slip and attractive molecular forces are considered. Comparison is made between the effects of unretarded and retarded van der Waals forces and Maxwell slip on collision efficiencies. Slip is calculated exactly for viscous drops using bispherical coordinates for motion along the drops’ line of centers. For water droplets in air, at drop radii between 10 and 30μm, drop inertia is important while the Reynolds based on the surrounding air is still small. The collision efficiency goes through a minimum and then approaches the Smoluchowski limit of no hydrodynamic interactions as the drop size and Stokes number become increasingly large. Viscous effects are most important at drop radii of about 15μm. For drops with a radius less than 10μm, the most significant factors are unretarded van der Waals forces, Maxwell slip, and retarded van der Waals forces, respectively. When van der Waals forces and slip are combined, the collision efficiencies for drops with radii of 10μm are significantly greater than the results of previous researchers. At an intermediate drop radius of 20μm, surrounding fluid inertia, as considered in earlier work, appears to lead to greater collision efficiencies at intermediate size ratios, while van der Waals forces, incorporated in the present study, cause larger values at smaller and larger size ratios. At a drop radius of 30μm, drop inertia dominates interactions, and similar results occur for both the current and prior investigations. Since temperature affects both density and viscosity, collision efficiencies can differ by a factor of two or more between 0 °C and 100 °C at certain drop radii. Change in the viscosity ratio itself leads to about a 7% difference in the collision efficiency between drops with internal circulation and solid spheres at room temperature.

Volume decomposition for multi-axis support-free and gouging-free printing based on ellipsoidal slicing

Continuous multi-axis printing has drawn more and more attention owing to its unique advantages of eliminating the need of support (at least in theory) when printing complex models with overhang features and significantly reducing the stair-step effect of the conventional three-axis printing. For continuous multi-axis printing, the printing layers are typically not planar but curved, so to capitalize the extra DOFs provided by the rotary axes of the printer. When a printing layer is concave (i.e., its curvature vector points inward at the printing point), the potential nozzle-layer local gouging becomes a serious concern, which is especially problematic for metal printing wherein the size of the nozzle head is usually large. Unfortunately, this convexity issue has received little attention in the existing curved slicing algorithms, making them prone to the local gouging quandary. In this paper, we propose a novel curved layer decomposition algorithm based on the use of (only the positive sides of) ellipsoidal surfaces. To facilitate the generation of ellipsoidal printing layers for an arbitrary freeform solid model with a complex topology (e.g., having a non-zero genus number), the powerful algebraic technique of skeletonization is employed by our algorithm to first decompose the model into a suitable set of sub-entities, for each of which a series of ellipsoidal printing layers are then generated, wherein the parameters of ellipsoidal layers are adaptively adjusted to satisfy the necessary constraints such as support-free and other requirements. Preliminary experiments in both computer simulation and physical printing of the proposed algorithm are conducted, and the results give a positive validation on the effectiveness and feasibility of the proposed methodology.

Computational and numerical analysis of AC optimal power flow formulations on large-scale power grids

Alternating current optimal power flow (AC-OPF) is a fundamental tool in electric utilities to determine optimal operation of the various resources. Typically, the AC-OPF problem uses power balance formulation containing voltages and power equations. Yet, there is no comprehensive comparison of the different AC-OPF formulations, especially for large-scale networks. This paper presents a detailed comparative evaluation of different formulations of the AC-OPF problem on networks ranging from 9-bus to 25,000 buses. Three different formulations: 1) power balance with polar voltages, 2) power balance with Cartesian voltages, and 3) current balance with Cartesian voltages are discussed in detail by comparing their characteristics, and numerical and computational performance. We compare the performance of the three methods in terms of computational speed, number of iterations, and number of non-zeros in Jacobian and Hessian matrix. The numerical results show that power balance polar formulation had the best performance on small number of bus system but on a large-scale test grid current balance cartesian outperformed the other two formulations.

Illuminating entanglement shadows of BTZ black holes by a generalized entanglement measure

We define a generalized entanglement measure in the context of the AdS/CFT correspondence. Compared to the ordinary entanglement entropy for a spatial subregion dual to the area of the Ryu-Takayanagi surface, we take into account both entanglement between spatial degrees of freedom as well as between different fields of the boundary theory. Moreover, we resolve the contribution to the entanglement entropy of strings with different winding numbers in the bulk geometry. We then calculate this generalized entanglement measure in a thermal state dual to the BTZ black hole in the setting of the D1/D5 system at and close to the orbifold point. We find that the entanglement entropy defined in this way is dual to the length of a geodesic with non-zero winding number. Such geodesics probe the entire bulk geometry, including the entanglement shadow up to the horizon in the one-sided black hole as well as the wormhole growth in the case of a two-sided black hole for an arbitrarily long time. Therefore, we propose that the entanglement structure of the boundary state is enough to reconstruct asymptotically AdS3 geometries up to extremal surface barriers.

Non-Hermitian skin effect beyond the tight-binding models

The energy bands of non-Hermitian systems exhibit nontrivial topological features that arise from the complex nature of the energy spectrum. Under periodic boundary conditions (PBCs), the energy spectrum describes rather generally closed loops in complex plane, characterized by integer nonzero winding numbers. Such nontrivial winding provides the topological signature of the non-Hermitian skin effect (NHSE), i.e., the macroscopic condensation of bulk states at the lattice edges under open boundary conditions (OBCs). In spite of the great relevance of band winding in the non-Hermitian topological band theory and the related NHSE, most of current results rely on tight-binding models of non-Hermitian systems, while exact Bloch wave function analysis of the NHSE and related topological band theory is still lacking. While tight-binding models can correctly describe narrow-band electronic states with a relatively weak degree non-Hermiticity, they are not suited to describe high-energy wide-band electronic states and/or regimes corresponding to strong non-Hermiticity. Here we consider the single-particle continuous Schr\"odinger equation in a periodic potential, in which non-Hermiticity is introduced by an imaginary vector potential in the equation, and show that the NHSE is ubiquitous under OBC and characterized by a nonvanishing integer winding number, even though the energy spectrum under PBC always comprises an open curve, corresponding to high-energy electronic states. We also show that the interior of the PBC energy spectrum corresponds to the complex eigenenergies sustaining localized (edge) states under semi-infinite boundary conditions.

Generalized r-Lambert Function in the Analysis of Fixed Points and Bifurcations of Homographic 2-Ricker Maps

This paper aims to study the nonlinear dynamics and bifurcation structures of a new mathematical model of the [Formula: see text]-Ricker population model with a Holling type II per-capita birth function, where the Allee effect parameter is [Formula: see text]. A generalized [Formula: see text]-Lambert function is defined on the 3D parameters space to determine the existence and variation of the number of nonzero fixed points of the homographic [Formula: see text]-Ricker maps considered. The singularity points of the generalized [Formula: see text]-Lambert function are identified with the cusp points on a fold bifurcation of the homographic [Formula: see text]-Ricker maps. In this approach, the application of the transcendental generalized [Formula: see text]-Lambert function is demonstrated based on the analysis of local and global bifurcation structures of this three-parameter family of homographic maps. Some numerical studies are included to illustrate the theoretical results.

Undecidable arithmetic properties of solutions of Fredholm integral equations

A basic problem in transcendental number theory is to determine the arithmetic properties of values of special functions. Many special functions, such as Bessel functions and certain hypergeometric functions, are E-functions which are a natural generalization of the exponential function and satisfy certain linear differential equations. In this case, there exists an algorithm which determines if f(α) is transcendental or algebraic if f(z) is an E-function and α∈Q‾⁎ is a non-zero algebraic number. In this paper, we consider the analogous question when f(z) satisfies an integral equation, in particular, a Fredholm integral equation of the first or second kind where the kernel and forcing term satisfy strong arithmetic properties. We show that in both periodic and non-periodic cases, there exists no algorithm to determine if f(0)∈Q is rational. Our results are an application of the undecidability of the Generalized Collatz Problem due to Conway [6].

Parametric dependence of bound states in the continuum in periodic structures: Vectorial cases

A periodic structure sandwiched between two homogeneous media can support bound states in the continuum (BICs) that are valuable for many applications. It is known that generic BICs in periodic structures with an up-down mirror symmetry and an in-plane inversion symmetry are robust with respect to structural perturbations that preserve these two symmetries. For two-dimensional (2D) structures with one periodic direction and the up-down mirror symmetry (without the in-plane inversion symmetry), it was recently established that some scalar BICs can be found by tuning a single structural parameter. In this paper, we analyze vectorial BICs in such 2D structures, and show that a typical vectorial BIC with nonzero wave numbers in both the translationally invariant and the periodic directions can only be found by tuning two structural parameters. Using an all-order perturbation method, we prove that such a vectorial BIC exists as a curve in the 3D space of three generic parameters. Our theory is validated by numerical examples involving periodic arrays of dielectric cylinders. The numerical results also illustrate the conservation of topological charge when structural parameters are varied, if both BICs and circularly polarized states are included. Our study reveals a fundamental property of BICs in periodic structure and provides a systematical approach for finding BICs in structures with less symmetry.

Spin-Chern insulator induced by pseudospin-orbit coupling in phononic crystals

The boundary modes of classical waves protected by the topology are of great significance for robust energy transmission and reliable information processing. Many endeavors have been made to realize topological insulators in electromagnetic, mechanical and acoustic systems. Previous studies on acoustic boundary modes mainly focused on the interface states at the domain walls between different topological phases of phononic crystals. In electromagnetic and mechanical systems, although helical boundary states have been observed, the pseudospin in them is conserved, thus these systems can be considered as two independent copies of Chern insulators. When the pseudospin conservation is broken, the topology cannot be described by Chern numbers, and the spin will vary in transport. This general case remains to be explored both in electronic and classical systems. In this work, we constructed a two-dimensional topological phononic crystal induced by pseudospin-orbit coupling, which hosts the gapless helical boundary modes at the edge of a phononic crystal. Since these boundary states originate from non-zero spin-Chern numbers, the system is called the spin-Chern insulator. We have observed these boundary states in experiments, and observed the spin-flipping transport in the H-shaped sample, proving the spin non-conservation of the boundary states. Different from the earlier work, this work demonstrates two important aspects: first, the acoustic topological insulator is induced by the pseudospin-orbit coupling, and possesses the gapless helical edge states on its boundary, thus is the first analogue of topological insulator for acoustic wave; second, the inherent spin conservation is broken, which expands and deepens the knowledge of current topological physics in classical and electronic systems. The helical boundary states may have potential applications in new topological acoustic devices.