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The paper presents experimental values of lateral and extension transmission ultrasonic waves speed and their absorbance coefficient obtained with the help of discrete immersed method in metal filled polymer auxetic samples with polyurethane matrix. Poisson’s ratio, real and imaginary parts of complex dynamic elastic modulus (Young’s modulus, shear modulus, bulk modulus) and mechanical losses tangent of angle for extension, lateral and bulk deformation have been calculated regarding paper’s results. Viscoelastic properties of polyurethane auxetic have been examined regarding different theoretical approaches. To support negative values of Poisson’s ratio, a filled polymer model with critical filler amount and auxetic deformation models have been used. Models structural characteristics for filled polyurethane auxetics have been defined. Systems modeling with solid bulky inclusions, that are able to absorb and to disseminate ultrasonic waves, enables to consider suchlike systems as complex density materials. It is shown that in certain ratio of wave parameters and environment structural and mechanical properties, resonance effects take place, regarding filler’s particles vibration as inclusions in general.

Dielectric (impedance) spectroscopy of liquid crystals is a powerful experimental technique. It is especially essential because liquid crystals in many applications are still controlled by the elec...

Circulating tumor cells are widely used as biomarkers of cancer. Although early detection of these cells is vital for diagnosis and prognosis of deadly cancer, it is still a challenging issue due to the complex matrix of blood and their low presence in the bloodstream. In the present study, we propose a micro-channeled lab-on-a-chip system using two distinct methods based upon dielectrophoretic force and electrical properties of cells to increase the cell detection capability and identification efficiency and accuracy. The dielectric properties of cells contribute to the difference between negatively charged residues on the cell surface. Firstly, the dielectrophoretic force is used to separate background cells; then, the proposed high-accuracy identification method is used to better examine and study the unidentified cells. In the next phase, by amplification of the current of the unidentified cells flowing through the nanoparticle plasmonic resonance effects, the microfluidics output efficiency is significantly improved. As a result, highly accurate cell identification is achieved by taking advantage of the nanoparticle plasmonic properties. Overall, nanoparticle scattering in the plasmonic resonance condition, as well as their plasmonic hybridization, can improve output signal-to-noise ratio.

The transmission of electronic substituent effects through a carbon-carbon triple bond has been investigated from the small changes induced by a variable substituent X on the geometry of the phenyl group in β-substituted phenylacetylenes, Ph−C≡C−X. The geometries of many such molecules were determined by quantum chemical calculations at the B3LYP/6-311++G** level of theory. The structural variation of the phenyl probe is best represented by a linear combination of the internal ring angles, termed SFPHA. Multiple regression analysis of SFPHA using appropriate explanatory variables reveals a composite polar effect. The main components are, in order of decreasing importance: (i) the field effect of the substituent, enhanced by field-induced π-polarization of the −C≡C− spacer, (ii) the resonance-induced field effect, and (iii) the electronegativity effect. These results are compared with those obtained for (E)-β-substituted styrenes, Ph−CH=CH−X, using the same statistical technique, applied to a structural parameter termed SFSTY. The comparison shows that in β-substituted phenylacetylenes, the field effect of the substituent plays a more important role, and the resonance effect a less important, than in (E)-β-substituted styrenes. This is a consequence of the greater polarizability of the C≡C bond as compared with the C=C bond. The role played by the electronegativity of the substituent is the same for the two sets of molecules. A peculiar feature of the −C≡C− spacer is that its π-system consists of two separate parts, corresponding to the two π-bonds that concur to the formation of the triple bond. Only the part orthogonal to the plane of the phenyl probe may interact with the probe π-system, making it possible to transfer π-electron density from substituent to probe, or vice versa. The part coplanar with the phenyl probe may exchange π-electron density with the substituent, but not with the probe. Thus, π-interactions between substituent, spacer, and probe depend critically on the electronic structure and conformation of the substituent. We have classified the substituents in three categories according to the different types of π-interactions that occur in β-substituted phenylacetylenes. First category substituents exchange π-electron density with the orthogonal part of the π-system of the spacer, and hence with the π-system of the probe. While the orthogonal part of the π-system of the spacer acts as a π-electron channel, the coplanar part cannot exchange electrons with the π-system of the phenyl probe. With second category substituents, the conformation of the molecule inhibits the exchange of π-electron density between substituent and probe. The substituent can only exchange π-electrons with the part of the π-system of the spacer that is coplanar with the phenyl probe. Third category substituents exchange π-electron density with both parts of the π-system of the spacer. While the π-charge transferred into the orthogonal part can be further delocalized into the π-system of the phenyl probe, the π-charge transferred into the coplanar part cannot and remains blocked in the spacer. From there, however, it gives rise to an inductive effect that polarizes the π-electron system of the phenyl probe. The π-charge distribution in 45 β-substituted phenylacetylenes and the corresponding (E)-β-substituted styrenes has been determined by Natural Atomic Orbital analysis at the B3LYP/6-311++G** level of theory. The results of the analysis support our classification of the substituents in three categories and reveal the existence of a number of important correlations involving charges as well as structural parameters.

The random transitions of ion channels between open and closed states are a major source of noise in neurons. In this study, we investigate the stochastic dynamics of a single Hodgkin–Huxley (HH) neuron with realistic, physiological channel noise, which depends on the channel number and the voltage potential of the membrane. Without external input, the stochastic HH model can generate spontaneous spikes induced by ion-channel noise, and the variability of inter-spike intervals attains a minimum for an optimal membrane area, a phenomenon known as coherence resonance. When a subthreshold periodic input current is added, the neuron can optimally detect the input frequency for an intermediate membrane area, corresponding to the phenomenon of stochastic resonance. We also investigate spike timing reliability of neuronal responses to repeated presentations of the same stimulus with different realizations of channel noise. We show that, with increasing membrane area, the reliability of neuronal response decreases for subthreshold periodic inputs, and attains a minimum for suprathreshold inputs. Furthermore, Arnold tongues of high reliability arise in a two-dimensional plot of frequency and amplitude of the sinusoidal input current, resulting from the resonance effect of spike timing reliability.

Scanning probes are widely used in industry due to high precision and efficiency. However, the insufficient dynamic performance of the probe, especially the first-order natural frequency, makes the measurement results under high-speed scanning easily interfered by the resonance effect. Based on Lagrangian dynamic model of the probe, this paper proposes a multi-objective optimization method for the three-dimensional (3D) structure, including a two-dimensional (2D) elastic mechanism and a ceramic stylus, and obtains an optimized probe with highly increased first-order natural frequency and sensitivity. The evaluation of the probe dynamics and scanning-deviation prediction shows that the optimized probe has a higher upper velocity limit within the same allowable measurement deviation and a better tolerance to resonance. Compared with the original probe, the optimized probe significantly suppresses the low-amplitude and high-frequency resonance components caused by the axial runout of the linear guide and improve the quality of the system response signals.

Coupling resonance effect of interface delamination of laminates excited by horizontal shear wave sources on the surface is studied by analytical methods based on forced propagation solutions deduced by surface perturbation methods, integral transformation methods and global-matrix methods. The influence of excitation sources on the interface shear stress is investigated. It is found that coupling resonance frequencies of interface shear stress are intrinsic properties of structures and are independent of excitation sources, at which even a very small perturbation can also lead to the interface stratification. The results provide the theoretical basis for layered and/or anti-layered design of laminates.

We studied the expansion of locally resonant complete band gaps in two-dimensional phononic crystals (PCs) using a double-sided stubbed composite PC plate with composite stubs. Results show that the introduction of the proposed structure gives rise to a significant expansion of the relative bandwidth by a factor of 1.5 and decreases the opening location of the first complete band gap by a factor of 3 compared to the classic double-sided stubbed PC plate with composite stubs. Furthermore, more band gaps appear in the lower-frequency range (0.006). These phenomena can be attributed to the strong coupling between the “analogous rigid mode” of the stub and the anti-symmetric Lamb modes of the plate. The “analogous rigid mode” of the stub is produced by strengthening the localized resonance effect of the composite plates through the double-sided stubs, and is further strengthened through the introduction of composite stubs. The “analogous rigid mode” of the stubs expands the out-of-plane band gap, which overlaps with in-plane band gap in the lower-frequency range. As a result, the complete band gap is expanded and more complete band gaps appear.

We theoretically investigate the energy relaxation rate of magnons and phonons near the resonance points to clarify the underlying mechanism of heat transport in ferromagnetic materials. We find that the simple two-temperature model is valid for the one-phonon/one-magnon process, as the rate of energy exchange between magnons and phonons is proportional to the temperature difference between them, and it is independent of temperature in the high temperature limit. We found that the magnon-phonon relaxation time due to the one-phonon/one-magnon interaction could be reduced to 1.48 $\mu s$ at the resonance point by applying an external magnetic field. It means that the resonance effect plays a significant role in enhancing the total magnon-phonon energy exchange rate, apart from the higher order interaction processes.

A suitable piezoelectric accelerometer mathematical model is proposed to extract a relationship of motion relative frequency as a function of natural frequency. This relationship helps to select appropriate accelerometer frequency range that minimizes measurement error and improves accuracy. It also allows deducing a formula relating the damping rate and the measurement error of the accelerometer. To protect the accelerometer from failure, the resonance phenomenon effect must be minimized. In order to achieve this objective, physical principle is modeled to find a precise relationship which can determine the accelerometer appropriate frequency range. The developed model was simulated and the obtained results have showed that the selection of the frequency range has minimized the measurement error, increased the accelerometer accuracy, and reduced the resonance effect. Finally a comparative study was conducted to show the importance of the obtained results compared to recent literatures.

The transmission of electronic substituent effects along chains of conjugated double bonds has been investigated by analyzing the small structural changes induced by a variable substituent X in the phenyl group of Ph–(CH=CH) n –X molecules (n = 2, 3, and 4). The structures of many such molecules with charged or dipolar substituents have been determined from quantum chemical calculations at the B3LYP/6-311++G** level of theory. The structural variation of the phenyl probe is best represented by a linear combination of the internal ring angles, termed S F PE (n = 2, 3, and 4). Multiple regression analysis of the S F PE parameters using appropriate explanatory variables reveals a composite electronic effect, the main component of which is the field effect of the variable substituent, enhanced by field-induced π-polarization of the polyenic chain. Also important is the role of resonance-induced field effects. An electronegativity term contributes significantly to the structural variation of the phenyl probe in (E)-β-substituted styrenes, Ph–CH=CH–X, but is marginally significant in Ph–(CH=CH)2–X molecules and not significant at all in Ph–(CH=CH)3–X and Ph–(CH=CH)4–X molecules. The structural substituent parameters S F PE2 , S F PE3 , S F PE4 , as well as S F STY from (E)-β-substituted styrenes, are all correlated to each other. However, even though the correlation coefficients are high, it appears unequivocally that the data points corresponding to dipolar substituents and those corresponding to charged groups are aligned along slightly different straight lines. An analysis of π-charge distribution in Ph–(CH=CH) n –X molecules (n = 1–4) has also been carried out. It appears that as the number of double bonds increases, the π-charge transmitted from the variable substituent to the hydrocarbon frame becomes larger, while the π-charge transmitted to the phenyl probe becomes smaller. In each of the three series of Ph–(CH=CH) n –X molecules (n = 2, 3, and 4), the π-charge of the phenyl probe is linked by an excellent nonlinear relationship to the corresponding structural substituent parameter S F PE (n = 2, 3, and 4). The effect of the variable substituent on the geometry of the polyenic chain has been studied by analyzing the alternation of C–C bond lengths along the chain in Ph–(CH=CH)4–X molecules. The alternation is most pronounced and regular when the variable substituent X is an uncharged group, irrespective of whether it is a π-acceptor or a π-donor. For the five strongest resonant substituents in our data set (namely, the charged groups CH2 +, CH2 −(c), NH−, O−, and N2 +), there is a region in the chain where the alternation between adjacent C–C bonds decreases and inverts, a structural feature known as geometric soliton.

It is well known that Fano effect usually requires the introduction of asymmetric (or breaking) in their structure designs. The smaller the degree of breaking, the more obvious the Fano effect. However, the small degree of breaking demands extremely precise manufacturing capabilities and levels. This paper proposes a novel robust metallic array structure that can achieve a Fano-like effect with a high [Formula: see text]-factor as 73, consisting of a square patch and a closed-ring resonator. This distinct Fano-like resonance originates from the interactions of quadrupole resonance mode and dipole resonance mode. Moreover, the effect of the size and conductivity of the square patch on the Fano effect are discussed, and the sensing performance of this structure is also discussed. These results will pave the way for designing practical sensors and optical switches in the terahertz frequency range.

The role of electronic substituent effects in determining the twist angle of 4-substituted biphenyls and the mechanism of their propagation through the biphenyl frame have been studied by quantum chemical calculations at the HF/6-31G* and B3LYP/6-311++G** levels of theory, carried out on 41 p-Ph–C6H4–X molecules in their equilibrium conformation. The twist angle φ about the C–C bond connecting the two benzene rings, ca 45° in unsubstituted biphenyl, almost invariably decreases when a para substituent is present. In the majority of cases the difference ∆φ = φ(X) − φ(H) is small, less than a couple of degrees; the decrease of φ becomes substantial only when the substituent is a charged π-donor or π-acceptor. Multiple regression analysis using appropriate explanatory variables indicates a quadratic dependence of ∆φ on the π-donor/acceptor ability of the substituent, and, to a lesser extent, on its field effect. The propagation of substituent effects through the biphenyl frame has been studied from the structural variation of the Ph group acting as a probe (ring B). This is best measured by a linear combination of the internal ring angles, termed S F BIPH(e) . Multiple regression analysis of S F BIPH(e) reveals a composite field effect, a substantial proportion of which is originated by resonance- and polarization-induced π-charges on the carbon atoms of the –C6H4– spacer (ring A). Extended conjugation between ring A and ring B, caused by resonance and polarization effects, gives rise to quadratic terms in the regression. The reliability of S F BIPH(e) as a measure of long-range polar effects is supported by correlations with various experimental parameters.

The nature and transmission mechanism of substituent effects in (E)-β-substituted styrenes, C6H5–CH=CH–X, have been investigated from the structural changes induced by a variable substituent on the phenyl group. The molecular structures of 46 (E)-β-substituted styrenes were determined from MO calculations at the B3LYP/6-311++G** level of theory. The structural variation of the phenyl probe is best represented by two orthogonal linear combinations of the internal ring angles, S F STY and S R STY . Regression analysis of S F STY using appropriate explanatory variables reveals a composite field effect, the main component of which originates from the long-range effect of the substituent enhanced by field-induced π-polarization of the vinylene spacer and resonance-induced field effects. The electronegativity of the substituent also plays a role in determining the value of S F STY . Comparison with coplanar 4-substituted biphenyls reveals that the components of the field effect in the two molecular systems are of the same nature (apart from the electronegativity contribution, which is not present in biphenyl derivatives). However, the structural variation of the phenyl probe is more pronounced in (E)-β-substituted styrenes due to the shorter distance between substituent and probe. Analysis of π-charge distribution shows that the aptitude of the substituents to exchange π-electrons with the styrene and coplanar biphenyl frames is nearly the same. Nevertheless, the π-charge variation on the phenyl probe of (E)-β-substituted styrenes is 57 % greater than the corresponding quantity in coplanar 4-substituted biphenyls. Thus, the vinylene spacer is more effective than the phenylene spacer in transmitting π-charges. The S R STY parameter is related to the amount of π-charge transferred from the –CH=CH–X moiety into the π-system of the benzene ring, or vice versa, due to the resonance effect of the variable substituent and, to a lesser extent, to field-induced π-polarization.

In recent years, all modern vehicles and transport means use a vast variety of sensors and transducers. The operation of all medical instruments is also based on sensors and transducers. Industry is also employing more and more transducers for the monitoring and control of production lines. Therefore, the sensing technology has been driven by the increasing needs for enhanced sensitivity, improved stability, high reliability, and lower costs. For this purpose, we have proposed and developed novel two LC resonant-type magnetoimpedance (LCMI) sensor devices utilizing soft magnetic microwires as a sensing element, giving an emphasis on the use of resonance effect from LC-components and the rapid permeability change of the magnetic microwires to significantly improve the sensitivity performance of sensors. This article aims to provide a comprehensive analysis of the design and operation of these devices. After a description of magnetic core materials, circuit designs and fabrication techniques is given, the details of all experimental measurements are presented. The characterizations of constructed LCMI sensor devices are systematically analyzed, and the physical origins of magneto-resonant phenomena, field, and frequency dependences in these LCMI sensor devices are addressed. Influences of processing parameters on the sensing characteristics of LCMI sensors are also discussed. This enables the optimal conditions to fabricate high-performance magnetic sensing devices.

Korean bell is hung with some air gap between the bell bottom and the ground. In addition, it has a peculiar acoustic element, so called resonance cavity below the bell. A proper design of the air gap and cavity size dramatically amplifies the bell sound by resonance effect. Bell interior cavity, air gap and resonance cavity consist of an acoustic cavity system. When the acoustic cavity frequency coincides with the natural frequency of the bell body, the frequency component is significantly amplified. On the Sacred Bell of the Great King Seongdeok, this study proposes a resonance condition of the cavity system considering air gap effect for the first time. With the exact dimension of the bell, boundary element analysis is performed using SYSNOISE. Finally, this study reveals how the temperature in season influences the resonance condition and proposes a concept of variable type resonance cavity. By using the variable type resonance cavity, the cavity size is controlled on site and exact resonance is available regardless of temperature difference in season.

Electronic substituent effects in 4-substituted 1-phenylcubane derivatives, Ph–C8H6–X, have been investigated from the structural changes caused by the substituent X. The molecular structures of 34 derivatives with charged or dipolar substituents have been determined from quantum chemical calculations at the HF/6-31G* and B3LYP/6-311++G** levels of theory. Geometrical variations caused by substitution appear both in the cubane framework and in the benzene ring, but the two kinds of changes show no correlation. The rather small changes in the benzene ring geometry are caused by long-range polar effects (field effects), while the larger changes in the cubane cage are controlled primarily by electronegativity effects. A structural parameter measuring the long-range polar effect of the substituent, S F CUB , has been derived from the geometry of the phenyl group acting as a probe. This parameter correlates well with the calculated gas-phase acidities of 4-substituted cubane-1-carboxylic acids, HOOC–C8H6–X, and with other indicators of long-range polar effects obtained from bicyclo[2.2.2]octane derivatives. The correlations can further be improved by introducing a resonance parameter as an additional explanatory variable. This indicates that the electron delocalization resulting from hyperconjugative interactions between substituent and cage modifies the long-range polar effect of the substituent. Strong hyperconjugative interactions between some charged substituents and the cubane cage result in remarkable variations in the cage geometry, superimposed onto those ascribed to electronegativity effects.

Fully Implantable hearing devices consist of a microphone that is implanted under the human skin. However after the implantation, the gain characteristics of the microphone are attenuated at the high frequencies because of the sound filtering effect of the skin and tissue. To solve this problems, we proposed an implantable microphone with an acoustic tube, which generates a resonance effect between the diaphragm and the acoustic transducer inside a case. By performing several experiments in water, it has been confirmed that the frequency response of the implantable microphone at high frequencies can be improved by use of the acoustic tube.

Data for the low-frequency magnetic susceptibility of a rotating magnetic fluid measured in a permanent bias field are presented. It is found that the susceptibility of the medium resonantly grows when the rotation frequency coincides with the measuring field frequency. Reasons for and mechanisms behind this phenomenon are discussed.

Semiconductor microring resonators are excellent fundamental building blocks for fabrication of Optoelectronic Integrated Circuits (OEICs), due to their large third-order nonlinearities enhanced by the resonance effect, compactness which can lead to ultrahigh device integration densities and monolithic integration capability. In this work the key role of the fundamental design parameters will be highlighted in order to evaluate microring resonators for novel photonic function applications. These applications include but not limited to wavelength conversion, all-optical regeneration, all-optical logic, and information transmission and the dependence of each device's performance on the above parameters will be analyzed emphasizing on the induced fabrication limitations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Top-emitting organic light-emitting diodes (OLEDs) with a microcavity structure are presented in this paper. We performed a finite element (FE) analysis of a trilayer OLED that was inserted between the reflective layer and the semi-reflective layer of a device. We carried out an optical analysis of this OLED device and calculated the optimal width between the reflective layer and the semi-reflective layer to consider the nnicrocavity effect. Our simulation revealed that the thickness of each layer can affect the recombination rate at the emission layer. We used five OLED devices. Device A is a reference device with a 42.5 nm hole transport layer (HTL), a 15 nnn emission layer (EML) and a 45 nm electron transport layer (ETL). We varied the thickness of the HTL of Device A to 20 nm and 65 nm, and designated these devices as Device B and Device C, respectively. We also varied the thickness of the ETL of Device A to 20 nm and 65 nm, and designated these devices as Device D and Device E, respectively. As the thickness of the HTL and the ETL are decreased, a higher recombination rate is achieved. However, the highest recombination rate does not necessarily correspond to the highest external quantum efficiency (EQE) owing to the resonance effect. Our simulation revealed that the overall thickness of the device seems to be a more significant factor owing to the path of light.

According to the main characters of overlapping underground chambers, the roof (floor) of two adjacent underground chambers is simplified to the mechanical model that is the beam with build-in ends. And vibration load due to blasting is simplified to harmonic wave. The catastrophic model of double cusp for underground chambers destabilization induced by blasting vibration has been established under the circumstances of considering deadweight of the beam, and the condition of destabilization has been worked out. The critical safety thickness of the roof (floor) of underground chambers has been confirmed according to the destabilization condition. The influence of amplitude and frequency of blasting vibration load on the critical safety thickness has been analyzed, and the quantitative relation between velocity, frequency of blasting vibration and critical safety thickness has been determined. Research results show that the destabilization of underground chambers is not only dependent on the amplitude and frequency of blasting vibration load, but also related to deadweight load and intrinsic attribute. It is accordant to testing results and some related latest research results of blasting seismic effect. With increasing amplitude, the critical safety thickness of underground chambers decreases gradually. And the possibility of underground chambers destabilization increases. When the frequency of blasting vibration is equal to or very close to the frequency of beam, resonance effect will take place in the system. Then the critical safety thickness will turn to zero, underground chambers will be damaged severely, and its loading capacity will lose on the whole.

High-pressure 57Fe Mossbauer measurements of octamethyl-ethynyl-ferrocene (OMFA) were performed using a diamond anvil cell (DAC) in order to clarify the pressure effects on the phase transition occurring at ~248 K. A sharp resonance can be seen at 300 K and 12.6 GPa, suggesting a pressure-induced recovery to a rather large Lamb-Mossbauer factor. The resonance effect gradually decreases with a decrease of the external pressure.

DFT calculations on molecules with intramolecular hydrogen bonds have been performed at B3LYP/6-311++G(d,p) level of theory. The investigated 2,4-dihydroxybut-2-ene-4-dial molecule and its derivatives contain two intramolecular H-bonded rings. Each ring is the resonance-assisted system. The results of calculations show that two rings within the same molecule do not cause an increase of the resonance effect. It is shown that the topological parameters such as features of bond critical points and ring critical points may be treated as measures of H-bond strength.

The valley physics in the two-dimensional graphenelike system has been put forward recently, and one of the key issues is to produce valley currents. We propose in this work to realize the topological valley resonance effect in graphene by using the time-dependent lattice vibration of optical phonon modes, which can pump out a noiseless and quantized valley current flowing into graphene leads. This optimal topological valley pump is protected by a nonzero valley Chern number and is robust against perturbations that could even break the time-reversal symmetry and valley conservation. The electrical measurement of the pumped valley currents is also discussed.

The properties of enamines depend on slight changes in reaction conditions or structural factors. From the analysis of the data which is available in the literature, B3LYP/6-311+G(3df,3pd)//MP2/6-31+G ∗∗ calculations and using the Taft and Topsom model of the intrinsic substituent effect in the basicity, we found a resonance effect that explains why vinylamine and N , N -dimethylvinylamine are both carbon and not nitrogen bases (the resonance factor for vinylamine increases carbon basicity by about 56 kcal/mol).

We measured polarized far-infrared reflectivity and Raman scattering spectra of SrCuO$_2$ single crystals. The frequencies for infrared-active modes were determined using an oscillator-fitting procedure of reflectivity data. The Raman spectra were measured at different temperatures using several laser energies $\omega_L$. In addition to eight of twelve Raman active modes, predicted by factor-group analysis, we observed a complex structure in the Raman spectra for polarization parallel to the {\bf c}-axis, which consists of Raman-allowed A$_g$ symmetry modes, and B$_{1u}$ LO infrared-active (Raman-forbidden) modes of the first and higher order as well as their combinations. The Raman-forbidden modes have a stronger intensity at higher $\omega_L$ than the Raman-allowed ones. In order to explain this resonance effect, we measured the dielectric function and optical reflection spectra of SrCuO$_2$ in the visible range. We show that the Raman-allowed A$_g$ symmetry modes are resonantly enhanced when a laser energy is close to $E_0$, while Raman-forbidden (IR-active) modes resonate strongly for laser line energies close to the electronic transition of higher energy gaps., Comment: to be published in Physica C

The melting transition of a charge-polydisperse dusty plasma crystal under the influence of a time-dependent oscillating field is studied within a simple model. The stochastic dynamics of the dust particles is modelled by a Fokker-Planck description. Using non-equilibrium computer simulations we detect a non-monotonic behaviour of the melting line as a function of the frequency of the external field. This is attributed to a cage resonance effect which is controlled by the intrinsic polydispersity of the sample. The results are qualitatively explained within a cage theory of the polydisperse solid combined with a generalized Lindemann rule of melting.

The coherent LO phonon–plasmon coupled modes (LOPC modes) in n-GaAs have been studied by using a spectrally resolved pump–probe measurement which is performed by detecting probe beams after passing through a bandpass filter with a bandwidth of 10 nm. As the detection wavelength of the probe pulse comes closer to the band edge (∼870 nm), the intensity of the lower branch of the LOPC mode (L- mode) is increased and the decay time becomes longer. The wavelength dependence of the intensity will result from the resonance effect of the probe light. The wavelength dependence of the decay time indicates that the decay of the L- mode will be related to the intraband relaxation of the photoexcited carriers coupled with LO phonon due to the electron–hole scattering in the presence of the plasmon.

Proceedings of the 1998 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) --3 August 1998 through 7 August 1998 -- San Francisco, CA, USA -- The magnetic linear dichroism (MLD) was used to study the magnetic properties of Ni-ultrathin film grown on ferromagnetic substrate Co(001). The MLD in photoemission has been measured for either the valence Ni3d states around the Ni3p threshold or 3p core level. Our dichroism measurements of the valence Ni3d states conclude that the resonance effect is present on MLD for `6 eV-satellite' in the valence band photoemission whereas the main valence band peak shows nearly same MLD signal for the both on and off resonance. It is shown for the thinner film that the dichroism from Ni and Co3p core levels shows same sign with each other. This means that the Ni and Co are ferromagnetically coupled. Ministry of Education, Culture, Sports, Science and Technology The authors would like to thank the staff members of the UVSOR facility for their help during the experiments. This work is partly supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture in Japan. YU received financial support from the Scientific and Technical Research Council of Turkey (TUBITAK).

Raman scattering spectra of GexS1−x glasses (0.25⩽x⩽0.4) have been studied as a function of incident photon energy (2.0 eV⩽Einc⩽2.8 eV). At x=0.33, an increase in the relative intensity of the 430 cm−1 Raman mode compared with that of the A1 mode is observed in the VV scattering configuration, with increasing incident photon energy, while no significant change is observed for the corresponding Raman peaks of crystalline GeS2. Localized band-tail states associated with sulfur lone-pair interactions on the structural units, such as Ge2S6 edge-sharing tetrahedra and S–S dimers, may play a central role in governing the resonance effect. The composition dependence of the resonance features and the polarization aspects are also examined.

We report on the time-resolved study of coherent folded acoustic phonons in GaAs/AlAs superlattices with different periods under resonance condition. The Fourier transform spectra of the time-domain data show that a strong sharp peak accompanying weak doublet peaks at the lower- and higher- frequency sides appears. From comparison of the peak frequencies with calculated dispersion curves of the folded longitudinal acoustic modes, these peaks are attributed to the folded acoustic modes with the A1 symmetry at and near the Brillioun zone center. Polarization measurements of the coherent folded acoustic modes show that these observed modes are nearly isotropic. The measurement of the phonon amplitudes at various excitation-energies indicates that the resonance at the heavy-hole exciton transition remarkably influences the oscillation amplitudes of the coherent phonons both at and near the zone center. The behavior of the observed coherent phonons is discussed in relation to the resonance effect.

The super-giant magneto-impedance (SGMI) effect in an LC-resonator consisted of a glass-coated amorphous CoBSiMn microwire was studied. The sudden changes of magnetoimpedance at near the resonance frequency were observed, and the maximum ratio of SGMI reached as much as 400,000% in the experiment by precise tuning frequency at the resonance frequency.

A micromechanical resonant vibration sensor (MRVS) is presented with a geometrical structure that is designed for the detection of vibrations in the low-frequency range. The MRVS is distinguished from conventional piezoelectric and micromechanical acceleration sensors by the utilization of the resonance effect. The signal-to-noise ratio increases significantly when the sensor is excited with the designed frequencies. The vibrational properties of the MRVS have been investigated in the laboratory. Examples of the sensor response to different vibrational sources are analysed under industrial conditions. The capability of the sensor principle for wear monitoring is discussed.

We have analyzed the order-disordering variance due to resonance effect and the nonlinear behavior of far infrared ray laser (FIRL)-biological system interaction. The analytic results show that the interaction between the living biological system and FIRL can produce resonance excitation effect, and so the original high ordered state of the system can be destroyed and thus the conformation variation in the system can be produced under further action of the laser. In addition, we have analyzed the nonlinear properties of the FIRL bio-molecule interaction and explained the mutagenesis effects of FIRL. The theoretic analysis is consistent with the results of FIRL mutagenesis breeding test.

In this chapter, the multi-negative conductance property detected at low temperatures in an SOI Lubistor with a 10-nm-thick silicon layer is described. Important aspects of the lateral low-dimensional tunneling process are examined by a theoretical formulation. A comparison of the characteristics of Lubistors with a 10-nm-thick or a 90-nm-thick silicon layer indicates that the strong two-dimensional confinement effect plays an important role in multi-negative conductance. The theory predicts that a resonance effect between two subband levels results in the multi-negative conductance in the Lubistor with the 10-nm-thick silicon layer. [Copyright 2000. The Japan Society of Applied Physics. Y. Omura, Two-dimensional quantization effect in indirect tunneling in an insulated-gate lateral pn-junction structure with a thin silicon layer, Japanese Journal of Applied Physics , vol. 39, pp. 1597-1603, 2000.]

Quantum chemistry method is employed to calculate the new Cotton-Mouton effect. New effect provides structure information. New rotation of Porphyrins is strong, and could be dramatic enhanced by resonance effect.

A periodic structure has been observed in the tunneling characteristics of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{ital x}} break junctions. The observed structure is explained by the electron-hole interference effect in the surface layer, which produces a periodic structure in the tunneling characteristics. Good qualitative agreement has been obtained between measured data and calculated with Arnold{close_quote}s proximity model characteristics. The observed effect indicates an important role of the proximity effect on surface sensitive properties of high-{ital T}{sub {ital c}} superconductors, and explains the reported discrepancy of energy-gap values for Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{ital x}}. {copyright} {ital 1996 The American Physical Society.}

Metallic artificial index gratings are composed of metallic sub-wavelength structures. Appropriately designed metallic artificial index gratings show strong resonance effects if the wavelength is varied. This effect is demonstrated for several gratings.

In the title compound, C21H22N2O3, the geometry of the heterodiene (N=C—C=C) indicates the presence of a resonance effect across the C—C bond. The heterodiene prefers the s-trans configuration. The mol­ecules aggregate as double layers parallel to the (101) plane. Consecutive layers, labelled ABAB…, are inversely related to one another.

Collisionless damping of geodesic acoustic mode (GAM) is analytically investigated by considering the finite-orbit-width (FOW) resonance effect to the 3rd order in the gyro-kinetic equations. A concise and transparent expression for the damping rate is presented for the first time. Good agreement is found between the analytical damping rate and the previous TEMPEST simulation result (Xu 2008 et al Phys. Rev. Lett. 100 215001) for systematic q scans. Our result also shows that it is of sufficient accuracy and has to take into account the FOW effect to the 3rd order.

Photoluminescence (PL) from GaAs quantum wells with widths from 50 AA to 300 AA and AlxGa1-xAs barriers (x=0.3 and 1) was studied under pressure up to 35 kbar at two temperatures (300 K and 77 K). We used (and compared) three types of pressure devices: gas cells, liquid cells and the diamond-anvil cell. Accurate values for the pressure variation of the PL energy were obtained. They reveal the small dependence on the parameters of the well, in agreement with the envelope-function calculation. Pressure shifts of the PL lines is the same at 77 K and at 300 K. In several samples we found the change of the pressure coefficient of the direct ( Gamma ) line at the Gamma -X crossover pressure. We interpret this as the resonance effect due to the mixing of the Gamma state in the well with the X continuum in the barriers. This means that the pressure dependence of the quantum-well lines should not be fitted with a single curve below and above the Gamma -X crossover pressure. From our results we obtain the linear pressure coefficient of the GaAs energy gap equal to 11.6 meV kbar-1. The deformation potential of the gap seems to be almost independent of pressure up to 15 kbar.

The phenomenological theory of the magnetoelectric resonance effect is considered. The method of calculating magnetoelectric coefficients from measurements is presented. The mechanism responsible for the magnetoelectric resonance effect is discussed.

First- and second-order Raman scattering has been studied in epitaxial AlAs grown by solid-source molecular-beam epitaxy. A strong resonant enhancement of dipole-forbidden one-LO and intrinsic two-LO-phonon scattering is observed for excitation at the band-gap energy ${\mathit{E}}_{0}$. Maxima in the second-order Raman spectrum for excitation both at and below the ${\mathit{E}}_{0}$ gap resonance are assigned to contributions from various critical points of the Brillouin zone. Published data of ab initio calculations of the AlAs phonon dispersions are found to be in good agreement with the measured frequency positions of the second-order Raman bands. In highly carbon-doped p-type AlAs layers the local vibrational mode of the carbon acceptor (${\mathrm{C}}_{\mathrm{As}}$) is observed at about 635 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$.