Frequency Dispersion Research Articles

Comparative evaluation of the heterozygous variant standard deviation as a quality measure for next-generation sequencing

Next-generation sequencing holds unprecedented throughput in terms of informational content to cost. The technology has entered the scene in laboratory diagnostics and offers flexible workflows in biomedical research. However, the rapid acquisition of genomic data also gives rise to a substantial fraction of sequencing artifacts, causing the detection of false-positive germline variants or erroneous somatic mutations. Consequently, there is a pressing need for efficient and practical quality assessment in sequencing projects. In this study, we investigate using heterozygous variant allele frequency (VAF) standard deviation (σ) for supplementary quality control. Whereas several proposed quality metrics are based on empirical assessments, the dispersion of the allele frequencies reflects a direct approximation of the inherent and discrete features of a diploid genome. Consequently, homologous chromosomes display heterozygous VAF of approximately 1/2. Based on the meta-analysis of 152 whole-exome sequencing data sets, we found that σ reflects both sequencing coverage and noise and can be effectively modeled. It is concluded that the relative comparison of heterozygous VAF σ provides a practical handle for quality assessment, even for samples afflicted with copy-number alterations. The approach can be implemented when performing whole-exome, whole-genome, or targeted panel sequencing and helps identify problematic samples, such as those retrieved from archived formalin-fixed paraffin-embedded tissue.

Landau damping of ion‐acoustic waves with simultaneous effects of non‐extensivity and non‐thermality in the presence of hybrid Cairns‐Tsallis distributed electrons

AbstractThe dispersion properties and Landau damping rate of ion‐acoustic waves (IAWs) with the hybrid Cairns‐Tsallis distributed (CTD) electrons and Maxwellian ions are investigated using the plasma kinetic model based on Vlasov‐Poisson's equations. For both super‐extensive (q < 1) and sub‐extensive (q > 1) plasmas, the dielectric response function, real frequency, and Landau damping rate of IAWs are derived. By taking the effect of θi, e (ion‐to‐electron temperature ratio) into account, it is found that with the increase of ion temperature, the real frequency and wave dispersion effects increase as well (for both super‐extensive and sub‐extensive cases). Exploring the properties of the Landau damping rate of IAWs with the simultaneous presence of non‐thermal parameter α and non‐extensive parameter q, a comparison of numerical and analytical results is presented. It is found that in different ranges of θe, i (electron‐to‐ion temperature ratio), on decreasing the values of the non‐extensive parameter and increasing values of the non‐thermal parameter, the weak damping rate is observed (vice versa) in super‐extensive or super‐thermal plasma, although the trend of the damping rate in sub‐thermal plasma is similar (as in the case of super‐thermal plasma) but is less weak. It is further revealed that the damping rate of IAWs in thermal plasmas (Maxwellian) is stronger than the damping rate of IAWs in the case of non‐thermal plasmas (CTD). The current study is applicable to provide deep insight and further allow the exploration of electrostatic plasma modes in different space and laboratory plasma environments where the hybrid CTD plasma exists.

Why is the beautyberry so colourful? Evolution, biogeography, and diversification of fruit colours in Callicarpa (Lamiaceae)

Fruit colour is essential to seed dispersal, speciation, and biological diversity in global ecosystems. The relationship between fruit-colour variation and species diversification has long been of interest in evolutionary biology, but remains poorly understood at the genus level. Here, we used Callicarpa, a typical representative of pantropical angiosperm, to analyse whether fruit colours are correlated with biogeographic distribution, dispersal events, and diversification rate. We estimated a time-calibrated phylogeny for Callicarpa and reconstructed ancestral fruit colour. Utilizing phylogenetic methods, we estimated the major dispersal events across the phylogenetic tree and the most likely fruit colours related to each dispersal event, and tested whether the dispersal frequencies and distances of the four fruit colours between major biogeographical areas were equal. We then tested whether fruit colours are correlated with latitude, elevation, and diversification rate. Biogeographical reconstructions showed that Callicarpa originated in the East Asia and Southeast Asia during the Eocene (∼35.53 Ma) and diverse species diverged mainly in the Miocene and lasted into the Pleistocene. Large-scale dispersal events were significantly associated with violet-fruited lineages. Furthermore, different fruit colours were markedly correlated with different latitudes and elevations (e.g., violet fruits were correlated with higher latitudes and elevations; red fruits and black fruits with lower latitudes; white fruits with higher elevations). Notably, violet fruits were statistically associated with highest diversification rates, driving fruit colour variation among different regions globally. Our results contribute to further understanding why fruit colour is so variable at the genus level of angiosperms in different areas around the world.

A Tale of the Scattering Lifetime and the Mean Free Path

The idea of applying the scattering lifetime calculated from the imaginary part of the zero temperature elastic scattering cross-section to study a hidden self-consistent damping in two spaces of importance for non-equilibrium statistical mechanics is proposed. It is discussed its relation with the classical phase space from statistical mechanics and the configuration space from nonrelativistic quantum mechanics. This idea is contrasted with the mean free path values in three elastic collision regimes. The main exercise is to study the behavior of a self-consistent probabilistic distribution function in a space we have called the reduced phase space since it is related to the scattering lifetime. This exercise has been solved in two unconventional superconductors for which several calculations are discussed. One of them is to obtain the scattering phase shift from the inverse strength of an atomic potential and the other is to build several phases with different nodal configuration of the superconducting order parameter and show that the imaginary self-consistent part of the scattering cross-section is always positive for two compounds: the triplet strontium ruthenate and the singlet doped with strontium lanthanum cuprate when three models of superconducting order parameters are used: the quasi-point, the point and the line nodal cases. We finally compare the frequency dispersion in the anomalous skin effect with singular shapes of the Fermi surface with the frequency dispersion in the scattering lifetime and their respective mean free paths. This idea is useful because it intuitively explores the nonlocality of this type of hidden self-consistent damping for those incoherent fermionic quasiparticles.

A simulation approach to predict electrostatic coalescence performance of water-in-oil emulsion using population balance model

ABSTRACT Electrostatic coalescence of the water droplets in water-in-oil (W/O) emulsion plays a significant role in demulsification process. As the droplets collide and aggregate with each other, the dispersed droplets may coalesce and separate from continuous phase. Several mechanisms simultaneously contribute to the complexity associated with droplets coalescence. Thus, an appropriate simulation approach is needed to predict electrostatic coalescence performance in W/O emulsion. In this work, the population balance model (PBM) was used to predict coalescence performance of W/O emulsion under electric field. The proposed approach is novel as it integrates various mathematical models to study dispersed droplets collision frequency considering Boltzmann motion, differential settlement, and electric field. Moreover, a new collision efficiency model, which is best proper for the droplet size between 1 μm and 100 μm, is also proposed to make the prediction model more accurate. The simulation results were verified by comparing with existing experimental datasets. After that, a sensitivity analysis was carried out to study parameters that affect electrostatic coalescence performance, such as electric field strength, dispersion permittivity, continuous viscosity, and collision efficiency coefficient. The results show that the higher voltage and droplet permittivity both lead to the greater electrostatic coalescence performance, but the increments are gradually smaller under the condition of neglecting the droplet fragmentation. With the increasing of continuous viscosity, the droplet size median significantly decreases at first and then flattens. Meanwhile, the performance of electrostatic coalescence is greater at bigger collision efficiency coefficient. But the variation of volume size median with collision efficiency coefficient is modest. The simulation approach proposed in this paper provides an in-depth understanding of the dispersed droplets collision in electric field, which provides useful insights for prediction of electrostatic coalescence performance of W/O emulsion in petroleum industries.

Tuned bipolar oscillating gradients for mapping frequency dispersion of diffusion kurtosis in the human brain.

Oscillating gradient spin-echo (OGSE) sequences have demonstrated an ability to probe time-dependent microstructural features, although they often suffer from low SNR due to increased TEs. In this work we introduce frequency-tuned bipolar (FTB) gradients as a variation of oscillating gradients with reduced TE and demonstrate their utility by mapping the frequency dispersion of kurtosis in human subjects. An FTB oscillating gradient waveform is presented that provides encoding of 1.5 net oscillation periods, thereby reducing the TE of the acquisition. Simulations were performed to determine an optimal protocol based on the SNR of kurtosis frequency dispersion-defined as the difference in kurtosis between pulsed and oscillating gradient acquisitions. Healthy human subjects were scanned at 7T using pulsed gradient and an optimized 23 Hz FTB protocol, which featured a maximum b-value of 2500 s/mm2 . In addition, to directly compare existing methods, measurements using traditional cosine OGSE were also acquired. FTB oscillating gradients demonstrated equivalent frequency-dependent diffusion measurements compared with cosine-modulated OGSE while enabling a significant reduction in TE. Optimization and in vivo results suggest that FTB gradients provide increased SNR of kurtosis dispersion maps compared with traditional cosine OGSE. The optimized FTB gradient protocol demonstrated consistent reductions in apparent kurtosis values and increased diffusivity in generated frequency dispersion maps. This work presents an alternative to traditional cosine OGSE sequences, enabling more time-efficient acquisitions of frequency-dependent diffusion quantities as demonstrated through in vivo kurtosis frequency dispersion maps.

Aerial dispersal of Raoiella indica Hirst (Acari: Tenuipalpidae): Influence of biotic and abiotic factors, dispersal potential and colonization rate

Aerial dispersal can occur in response to both internal state of individuals and environmental conditions and probably contributed to the expansion of red palm mite Raoiella indica throughout the American continent within a decade. We report here experiments using wind tunnel in the laboratory and adhesive traps in the field to identify general aspects and precursors of R. indica’s aerial dispersal. Wind tunnel analyses indicated that dispersal rates increased with increasing wind speed up to 15 m/s and decreased with increasing population density. Although adult male and immature were dispersed by wind, adult females showed the highest frequency of dispersal. Mating status and 24 h food deprivation had no significant influence on the aerial dispersal of this species. In the field, the dispersal was also mainly observed among adult females. The number of captured mites increased progressively with height, up to the highest assessed state (4.8 m), and up to a distance of 48 m from infested coconut palms, at which colonization rates were equivalent to 1.4 × 105 mites/plant, although it was lower at the distance of 64 m (farthest assessed distance) from the source. The results identify conditions that elicit R. indica’s dispersal, and characterize its dispersal potential and colonization rates, allowing an ecological understanding of this invasive mite species.

Hot Carrier Transfer in PtSe2/Graphene Enabled by the Hot Phonon Bottleneck.

The charge transfer (CT) process of two-dimensional (2D) graphene/transition metal dichalcogenides (TMDs) heterostructures makes the photoelectric conversion ability of TMDs into a wider spectral range for the light harvester and photoelectric detector applications. However, the direct in situ investigation of the hot carrier transport in graphene/TMDs heterostructures has been rarely reported. Herein, using the optical pump and a terahertz (THz) probe (OPTP) spectroscopy, the CT process from graphene to five-layer PtSe2 in the PtSe2/graphene (P/G) heterostructure is demonstrated to be related to the pump fluence, which is enabled by the hot phonon bottleneck (HPB) effect in graphene. Furthermore, the frequency dispersion conductivity and the THz emission spectroscopy of the P/G heterostructure confirmed the existence of interlayer CT and its pump fluence-dependent behavior. Our results provide in-depth physical insights into the CT mechanism at the P/G van der Waals interface, which is crucial for further exploration of optoelectronic devices based on P/G heterostructures.

A Novel FDTD Approach Considering Frequency Dispersion of FR-4 Substrates for Signal Transmission Analyses at GHz Band

High-speed digital signaling can cause various signal integrity and electromagnetic interference problems. Signal attenuation and distortion can be observed in the gigahertz band owing to the frequency dispersion of substrates. In this article, we propose a frequency-dependent finite-difference time-domain (FDTD) approach for the numerical analyses of flame-retardant type-4 (FR-4) substrates. The proposed FDTD approach provides accurate broadband solutions because it can take into account the frequency dispersion of the substrate. First, the broadband complex permittivity of FR-4 substrates was measured using a balanced-type circular disk resonator and fitted into a Djordjevic model for the FR-4 substrates. Second, we adapted the fast inverse Laplace transform and Prony methods to find the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> -domain expressions and incorporate them into the FDTD formulation.The validity of the proposed approach was demonstrated by comparing the numerical and experimental results of the differential insertion loss and phase constant of differential microstrip lines. Both results were in good agreement, indicating the validity and usefulness of the proposed approach for simulations of broadband signal transmission in FR-4 substrates.

The Kurtz-Perry powder technique revisited: A case study on the importance of reference quality and broadband nonlinear optical measurements using LiInSe2

The Kurtz-Perry powder technique (KPPT) is widely utilized for the rapid characterization of newly grown nonlinear optical (NLO) materials available in pristine powder form. It assesses the effective nonlinear susceptibility of randomly oriented powder in comparison with a reference material. This technique becomes especially versatile when equipped with a broad wavelength range and intensity tunability because it provides key NLO properties of the materials under investigation, such as the frequency dispersion of the NLO susceptibility, phase-matching (PM) range, and laser-induced damage threshold (LIDT) as a guideline. In this study, wavelength-dependent NLO experiments (λ= 1100 – 3700 nm) were conducted on polycrystalline LiInSe2, prepared by high-temperature, solid-state synthesis. Our LiInSe2 was found to be phase-matchable for λ> 2500 nm and the effective NLO susceptibility was estimated as 20.0 ± 1.9 pm/V, assessed at the static limit using commercial-grade single crystals of AgGaS2 and AgGaSe2 that were ground to powders. Alternatively, the effective NLO susceptibility was determined to be twice as large, ~40 pm/V, when utilizing a homemade, microcrystalline AgGaSe2 reference at the static limit. This severe overestimation of the NLO susceptibility that can occur while working with a homemade standard underscores the importance of using a commercial-grade reference with the KPPT. Furthermore, this study also discusses the LIDT of LiInSe2 based on intensity-dependent SHG at 1064 nm with picosecond pulses, and compares with those of the commercial-grade AgGaS2 and AgGaSe2, determined under identical conditions. As defect levels can cause widely varying apparent color, thus optical bandgap, in LiInSe2, this study stresses the importance of using a high-quality standard when exploiting the KPPT for NLO materials characterization. The role of defects is discussed in terms of χ2, phase matching onset and LIDT, parameters that predominantly affect the evaluation of new NLO materials.

Off-equatorial effects of the nonlinear interaction of VLF chorus waves with radiation belt electrons

Nonlinear processes are involved in both the growth of VLF chorus waves and the energization of radiation belt electrons trapped in the wave potential. Nonlinear theory has led to analytic formulae describing both these processes. To investigate these processes, observations from the Van Allen Probes twin spacecraft provide simultaneous in situ information on VLF chorus waves, radiation belt and injected electrons, and local plasma parameters. We combine the theoretical treatment summarized by Omura (2021) with these in situ observations to investigate the characteristics and effects of nonlinear radiation belt processes at the off-equatorial location of the spacecraft observations. We show the smooth phase transition between initial subpackets of chorus wave elements, conducive to extended trapping and enhancement of resonant electrons. The structure of the chorus wave element changes as it propagates away from the equator. Frequency dispersion due to the variation of parallel wave group velocity with frequency contributes to the chorus waveform frequency sweep rate observed at an off-equatorial location. Nonlinear damping at the local value of ½ fce progressively erodes wave amplitude at frequencies above ½ fceEQ. We examine the important dependencies of the nonlinear inhomogeneity factor on the time rate of change of the wave frequency and the field-aligned gradient of the magnetic field and discuss their implication for the energization of trapped non-relativistic and MeV electrons. The 0.5–2% energy gain we find for 3–6 MeV seed electrons indicates that prompt local acceleration of highly relativistic and ultra-relativistic radiation belt electrons can take place directly through their nonlinear interaction with an individual VLF chorus wave element.

Degradation of NO-nitrided SiC MOS interfaces by excimer ultraviolet light irradiation

The impact of excimer ultraviolet (UV) light irradiation on SiO2/SiC(0001) and (112̄0) interfaces was examined to get insight into the effect of NO nitridation. While NO nitridation appears to be effective in passivating the electron traps at the SiO2/SiC interfaces, we found that the nitridation induces additional traps that are not active until UV light is irradiated. The traps include those causing hysteresis and frequency dispersion in the C–V characteristics and those affecting the long-term reliability of MOS devices. A non-nitrided SiO2/SiC interface was less sensitive to UV light, indicating the instability of the nitrided SiC MOS structure.

Time-dependent exchange creates the time-frustrated state of matter

Magnetic systems governed by exchange interactions between magnetic moments harbor frustration that leads to ground state degeneracy and results in the new topological state often referred to as a frustrated state of matter (FSM). The frustration in the commonly discussed magnetic systems has a spatial origin. Here we demonstrate that an array of nanomagnets coupled by the real retarded exchange interactions develops a new state of matter, time frustrated matter (TFM). In a spin system with the time-dependent retarded exchange interaction, a single spin-flip influences other spins not instantly but after some delay. This implies that the sign of the exchange interaction changes, leading to either ferro- or antiferromagnetic interaction, depends on time. As a result, the system’s temporal evolution is essentially non-Markovian. The emerging competition between different magnetic orders leads to a new kind of time-core frustration. To establish this paradigmatic shift, we focus on the exemplary system, a granular multiferroic, where the exchange transferring medium has a pronounced frequency dispersion and hence develops the TFM.

Design of a broadband Doherty power amplifier with a modified load modulation network

This article proposes a modified load modulation network (LMN) to adjust the structure of the traditional Doherty power amplifier (DPA) by changing one λ/4 microstrip line at the output of the main power amplifier into two in the traditional DPA and connecting a terminal open-circuit λ/2 line at the junction point which can reduce the frequency dispersion effect to achieve expanding bandwidth while maintaining saturation efficiency and back-off efficiency. A 2.6–3.6 GHz DPA is designed and fabricated for verification. The measured results show that the saturated output power is 42.5–44 dBm and the saturated efficiency is between 63% and 69% in target band with a gain from 8.5 to 9.5 dB. At 6 dB output power back-off, the drain efficiency is 44%–50%. And the adjacent channel power ratio (ACPR) is better than −32 dBc.

Acoustoelastic equations and Lamb waves dispersion characteristics of finitely deformed biological soft tissues with the growth-mechanical coupling

Acoustoelastic equations, especially the incremental constitutive law and the constitutive parameters associated with the growth increment, were presented for biological soft tissues coupling the growth and the mechanical effects. Both the initial growth deformation and the growth increment make biological tissues different from the general soft materials in acoustoelastic equations. Lamb waves dispersion in two finitely deformed biological soft layers was then investigated to explore the wave dispersion in biological tissues. The frequency dispersion equations were derived from which characteristics of wave dispersion of the first two modes were discussed. The influence of the predeformation and the external load on Lamb waves dispersion was quantitatively examined. It is found that some special dispersion phenomena such as the mode vanishment, frequency cut-off, frequency block, frequency pass and frequency gap may come up in Lamb waves dispersion. These dispersion features are dependent on the existence of phase velocity limits, the two-layer structure and the type of predeformation. Moreover, phase velocity limits were analytically deduced from the dispersion equations for the pre-stretched biological soft tissues. The elastic predeformation and the mechanical properties of biological tissues can then be determined from phase velocity limits, which provides a potential method to distinguish the growth deformation.

Characterization of the topography generated by low plasticity burnishing using advanced techniques

This work investigates the surface topography of AISI 304 austenitic stainless steel after low plasticity burnishing through the evaluation of the average surface roughness (Ra), surface texture direction, areal power spectral density (APSD), scale-sensitive fractal analysis and continuous wavelet transform (CWT). The reason for adopting these approaches resides in the fact that traditional amplitude profile parameters neglect dynamic aspects of the process and geometric features of the burnished surface. The direction, periodicity and anisotropy of the surface texture were influenced by number of passes and burnishing speed and, in general, less severe plastic strain conditions tended to produce surfaces with strongly anisotropic characteristics, preferred direction of motifs, with power spectrum indicating a well-defined spatial frequency of peaks, lower fractal complexity and uniform profile distribution. The increase in surface strain severity produced surfaces with more diffuse directional characteristics, which tended to present surface isotropy, higher spatial frequency dispersion of the peaks and higher fractal complexity. Furthermore, the transition from an anisotropic to an isotropic surface can occur without changes in the average surface roughness. The continuous wavelet transforms analysis indicated a dynamic variation on the surface plastic strain when burnishing. The intermediary burnishing speed induced a strong disturbance with loss of periodicity of the roughness profile, resulting in a remarkable influence on the roughness profile in small scales. The increase in number of passes elevated the plastic strain severity, affecting the surface macrogeometric profile. The isotropic surface promoted a less severe stress concentration, reducing the tensile stresses and retarding crack nucleation, thus increasing the fatigue considerably.

Low-order continualization of an anisotropic membrane lattice with next-nearest interactions. Enhanced prediction of its dynamic behaviour

In this paper, a novel anisotropic membrane lattice with nearest and next-nearest interactions (long-range forces) has been continualized through different standard and non-standard continualization procedures, which enables the development of new non-classical continuum models capable of accurately capturing the scale effects, present in the matter due to its discrete nature. The performance of these continuum models is assessed by means of both dispersion and natural frequencies analyses, where the discrete model is considered as a reference. In addition, the appearance of certain physical inconsistencies in some of the developed models is analysed, concluding that these only appear for those developed with continualizations based on Taylor expansion. Interestingly, the non-standard models suitably capture the dispersive behaviour of the discrete one, without both physical inconsistencies and higher-order spatial derivatives, thus avoiding the need for extra boundary conditions when finite solids are involved.

A study on the electrical properties of flux grown 0.91PZN-0.09PT single crystals for high-performance piezoelectric and pyroelectric device applications

In the present work, large-size piezoelectric single crystals of 0.91[Pb(Zn1/3Nb2/3)O3]-0.09PbTiO3 (PZN-9PT) have been grown by high-temperature flux method. Rietveld refinement analysis of X-ray diffraction data demonstrates the existence of monoclinic [Cm and Pm] phases, further supported by electron diffraction studies. PZN-9PT single crystal shows broad and diffused dielectric response peaks at 354 K and 443 K with noticeable frequency dispersion identified from temperature-dependent dielectric measurements. The 001 oriented PZN-9PT elements sliced from the grown single crystals display a remnant polarisation (Pr) of 30 µC/cm2, saturation polarization (Ps) of 33 µC/cm2, and an enhanced piezoelectric strain of 0.3 %. In addition, the piezoelectric coefficients d33, d31 and electric field-induced strain d33∗ measured by the direct method is 2100 pC/N, 1650 pC/N and 2500 pm/V, respectively. The mechanism behind the enhanced piezoelectric properties of PZN-9PT is explained with reference to the stabilization of the monoclinic phase and polarization rotation mechanisms. Further, the pyroelectric coefficient, p measured to be 11.31 × 10−4 C/m2 K at room temperature and 51.22 × 10−4 C/m2 K at the ferroelectric to the paraelectric phase transition temperature. The enhanced piezoelectric and pyroelectric properties of PZN-9PT make them suitable for high-performance piezoelectric transducers, actuators at ambient temperature and pyroelectric sensors at elevated temperature, respectively.

Anomalous dielectric response in the triple perovskite ruthenate Ba3BiRu2O9

We have investigated the magnetic, dielectric and thermal properties of the S = 1 magnetic dimer Ba3BiRu2O9, which is known to exhibit a spin-gap opening in conjunction with a first-order magneto-elastic phase transition at ∼175 K. Above the spin-gap temperature, the temperature dependence dielectric constant shows a peak like feature with pronounced frequency dependence. The critical slowing down behavior of this frequency dispersion suggests that a ferroelectric relaxor like electrical glassy state exists above the spin-gap opening temperature regime. The extermination of frequency dispersion—right at the magneto-elastic phase transition, is suggestive of a strong coupling between the lattice and charge-spin degrees of freedom in this triple perovskite system.

Investigation of the Physical Mechanism of Acoustic Attenuation in Viscous Isotropic Solids

The traditional acoustic attenuation coefficient is derived from an analogy of the attenuation of an electromagnetic wave propagating inside a non-ideal medium, featuring only the attenuation of wave propagation. Nonetheless, the particles inside viscous solids have mass, vibrating energy, viscosity, and inertia of motion, and they go through transient and damping attenuation processes. Based on the long-wavelength approximation, in this paper, we use the energy conservation law to analyze the effect of the viscosity of the medium on acoustic attenuation. We derive the acoustic attenuation coefficient by combinations of the dynamical equation of a solid in an acoustic field with conventional longitudinal wave propagation under a spring oscillator model. Considering the attenuation of propagating waves and the damping attenuation of particle vibration, we develop a frequency dispersion relation of phase velocity for the longitudinal wave propagating inside viscous solid media. We find that the acoustic impulse response and vibrational system function depends on the physical properties of the viscous solid media and their internal structure. Combined with system function, the impulse response can be an excellent tool to invert the physical properties of solids and their internal structures. We select a well-known rock sample for analysis, calculate the impulse response and vibrational system function, and reveal new physical insight into creating acoustic attenuation and frequency dispersion of phase velocity. The results showed that the newly developed acoustic attenuation coefficients enjoy a substantial improvement over the conventional acoustic attenuation coefficients reported in the literature, which is essential for industrial applications; so are the dispersion characteristics.