for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> PHYSICS (Total: 800 journals)
    - ELECTRICITY AND MAGNETISM (9 journals)
    - MECHANICS (21 journals)
    - NUCLEAR PHYSICS (49 journals)
    - OPTICS (86 journals)
    - PHYSICS (578 journals)
    - SOUND (25 journals)
    - THERMODYNAMICS (32 journals)

PHYSICS (578 journals)

The end of the list has been reached or no journals were found for your choice.
Journal Cover Modern Physics Letters B
  [SJR: 0.222]   [H-I: 33]   [10 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0217-9849 - ISSN (Online) 1793-6640
   Published by World Scientific Homepage  [118 journals]
  • Investigation of interface and oxygen vacancy of
           Pt/Ba[math]Sr[math]TiO[math]/MgO interdigital capacitor through sequent
           low and high temperature annealings
    • Abstract: Modern Physics Letters B, Volume 31, Issue 11, 20 April 2017.
      Pt/Ba[math]Sr[math]TiO[math] (BST)/MgO interdigital capacitor (IDC) was patterned from a Pt/BST/MgO heterostructure, in which Pt film was prepared by sputtering and epitaxial BST film by pulsed laser deposition (PLD). Post-annealings at 200[math]C and 750[math]C were successively applied to the sample in order to investigate the impacts of post-annealing on the structural and dielectric properties of the IDC. The dielectric constants of the sample for as-grown and annealed at 200[math]C and 750[math]C were 1529, 1717 and 1800 and the corresponding dielectric losses were 0.073, 0.062 and 0.059, respectively. This is attributed to the fact that 200[math]C annealing can improve the quality of Pt/BST interface and 750[math]C annealing can reduce the oxygen vacancies in BST film. Our results provide the evidences that both the interface and oxygen vacancy play very important roles in dielectric properties of BST-based IDCs.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-21T06:55:14Z
      DOI: 10.1142/S021798491750124X
       
  • Peculiarities in the concentration dependence of the superconducting
           transition temperature in the bipolaron theory of Cooper pairs
    • Abstract: Modern Physics Letters B, Volume 31, Issue 11, 20 April 2017.
      It is shown that the bipolaron theory of Cooper pairs suggests that there is a possibility for a superconducting phase to exist at low and high levels of doping and be absent at the intermediate level of doping. The results obtained possibly to imply the universal character of 1/8 anomaly.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-21T06:55:01Z
      DOI: 10.1142/S0217984917501251
       
  • Research on local resonance and Bragg scattering coexistence in phononic
           crystal
    • Abstract: Modern Physics Letters B, Volume 31, Issue 11, 20 April 2017.
      Based on the finite element method (FEM), characteristics of the local resonance band gap and the Bragg scattering band gap of two periodically-distributed vibrator structures are studied. Conditions of original anti-resonance generation are theoretically derived. The original anti-resonance effect leads to localization of vibration. Factors which influence original anti-resonance band gap are analyzed. The band gap width and the mass ratio between two vibrators are closely correlated to each other. Results show that the original anti-resonance band gap has few influencing factors. In the locally resonant structure, the Bragg scattering band gap is found. The mass density of the elastic medium and the elasticity modulus have an important impact on the Bragg band gap. The coexistence of the two mechanisms makes the band gap larger. The band gap covered 90% of the low frequencies below 2000 Hz. All in all, the research could provide references for studying the low-frequency and broad band gap of phononic crystal.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-21T06:54:59Z
      DOI: 10.1142/S0217984917501275
       
  • Infrared traffic image enhancement algorithm based on dark channel prior
           and gamma correction
    • Abstract: Modern Physics Letters B, Ahead of Print.
      The infrared traffic image acquired by the intelligent traffic surveillance equipment has low contrast, little hierarchical differences in perceptions of image and the blurred vision effect. Therefore, infrared traffic image enhancement, being an indispensable key step, is applied to nearly all infrared imaging based traffic engineering applications. In this paper, we propose an infrared traffic image enhancement algorithm that is based on dark channel prior and gamma correction. In existing research dark channel prior, known as a famous image dehazing method, here is used to do infrared image enhancement for the first time. Initially, in the proposed algorithm, the original degraded infrared traffic image is transformed with dark channel prior as the initial enhanced result. A further adjustment based on the gamma curve is needed because initial enhanced result has lower brightness. Comprehensive validation experiments reveal that the proposed algorithm outperforms the current state-of-the-art algorithms.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-20T09:23:14Z
      DOI: 10.1142/S0217984917400449
       
  • A 0.975 [math]W 10-bit 100 kS/s SAR ADC with an energy-efficient and
           area-efficient switching scheme
    • Abstract: Modern Physics Letters B, Ahead of Print.
      A 10-bit successive approximation register (SAR) analog-to-digital converter (ADC) with an energy-efficient and area-efficient switching scheme was presented. By using C-2C dummy capacitor and an extra reference [math] for the last capacitor, the proposed switching scheme achieves 97.65% switching energy saving, 87.2% capacitor area reduction and 47.06% switches reduction, compare to conventional switching scheme. The ADC was implemented in a 180 nm CMOS technology 1.8 V power supply, at sampling rate of 100 kS/s, the ADC achieves an SNDR of 57.84 dB and consumes 0.975 [math], resulting in a figure-of-merit (FOM) of 15.3 fJ/conversion-step.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-20T09:23:13Z
      DOI: 10.1142/S0217984917400516
       
  • Dispersion characteristics and compensation in the POLMUX coherent optical
           communication system
    • Abstract: Modern Physics Letters B, Ahead of Print.
      The trend of high-speed optical communication is to realize large capacity, fast speed and long haul transmission. However, the dispersion in an optical fiber link can cause signals distortion or even inter symbol interference (ISI). With increasing signal rate and transmission distance in the optical communication system, the development of high-speed optical fiber communication is restricted seriously. This paper is focusing on the dispersion characteristics and compensation of the polarization multiplexing (POLMUX) coherent optical communication system: (i) to study on dispersion theoretically, e.g., chromatic dispersion (CD), polarization mode dispersion (PMD) and dispersion tolerance; (ii) to analyze and compare the performance of dispersion with various 16-ary modulation formats; (iii) to compensate dispersion by the classical dispersion compensation methods.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-20T09:23:13Z
      DOI: 10.1142/S0217984917400541
       
  • A hierarchical energy efficiency evaluation model of numerical control
           workshop
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Energy consumption of numerical control (NC) workshop has lots of characteristics, such as hierarchy, multi-sources and time-varying. These characteristics make the modeling and evaluation of energy consumption in NC workshop very difficult. In this paper, a novel hierarchical model of the energy consumption in NC workshop is presented. Then, the calculation methods of energy efficiency in each layer are given. Furthermore, the acquisition method of the energy consumption data which is easily implemented is put forward and an experiment in NC workshop was made to illustrate the effectiveness of the proposed energy consumption model. The experimental results showed that the model cannot only describe the energy consumption effectively but also provide a way to identify the bottleneck of energy consumption in the workshop.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-20T09:23:13Z
      DOI: 10.1142/S0217984917400589
       
  • Stochastic gradient identification algorithm for nonlinear system modeling
           in wind power curtailment prediction
    • Abstract: Modern Physics Letters B, Ahead of Print.
      This paper considered the parameter identification problem of Hammerstein finite impulse response models and a novel stochastic gradient identification algorithm is derived for the Hammerstein system modeling. By using the gradient search principle and minimizing the quadratic criterion functions, the presented stochastic gradient identification algorithm has a better computational efficiency. The given simulation validates that the proposed algorithm can identify the wind power characteristic curve accurately and contributes to calculate the wind power curtailment prediction.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-20T09:23:12Z
      DOI: 10.1142/S0217984917400577
       
  • Electrical characteristics of semiconductor bridge initiator-automobile
           airbag igniters
    • Abstract: Modern Physics Letters B, Ahead of Print.
      To study the ignition characteristics of semiconductor bridges (SCB) for automobile airbag igniters, a model was proposed to compute the electrical characteristics of SCB based on the structural characteristics, resistance properties, and the working process of the bridge. Numerical simulation was conducted to analyze the voltage and current trends at two ends of bridges with various geometric dimensions and those with identical geometric dimensions and oxide layers of different thicknesses. Voltage–current curves for bridges of three different dimensions were obtained through numerical simulation. Bridges of larger geometric dimensions were found to require higher voltage to reach the melting point, which means higher energy input is required.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-19T08:31:04Z
      DOI: 10.1142/S0217984917400188
       
  • Application of BP neural network in acoustic wave measurement system
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Acoustic wave measurement technology is the supporting technology in acoustic wave field. It is important to study acoustic wave with high precision and reliability testing equipment and scientific testing methods. The mathematical model of this acoustic wave measurement system was analyzed on the building of the system. The BP neural network algorithm was used in order to attain the higher accuracy for the acoustic wave measurement system. Frequency domain calibration was carried out by which the amplitude/frequency character curve of this system could be obtained. Then the model of the system was established by BP neural network algorithm. Finally, the validity of the established model was tested. The conclusion was that the math model reflected the original acoustic wave measurement system’s character through the regression result in the frequency domain.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-19T08:31:04Z
      DOI: 10.1142/S0217984917400528
       
  • Vision-based fast location of multi-bar code in any direction
    • Abstract: Modern Physics Letters B, Ahead of Print.
      The automatic location of the bar code is a key step in the bar code image recognition system. It is extremely confined that the generalization of the traditional bar code localization algorithms due to the requirements of both direction and quality of bar code, and most of them are only aimed at the single barcode localization. In this paper, we have proposed a novel multi-barcode location algorithm in arbitrary direction based on the accumulation of the linear gray value. First, the line coordinates of the barcode region is determined by the image normalized cross-correlation algorithm. Then the center line of gray value of cumulative distribution is used to analyze the barcode boundary and to determine the number of bar code within the region. Finally, the precise positioning of the barcode region is obtained. The experiments have demonstrated that our proposed method can be used to identify all the bar codes in any area, and automatically locate the bar codes in any direction.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-19T03:00:44Z
      DOI: 10.1142/S0217984917400474
       
  • Optical communication equalized technique suitable for high-speed
           transmission
    • Abstract: Modern Physics Letters B, Ahead of Print.
      To solve the phase distortion and high error rate in optical signal transmission, an equalized technique is proposed, which aims to improve the constant modulus algorithm (CMA). In order to correct phase rotating and reduce the error rate with 64 quadrature amplitude modulation (QAM), the method takes the mean square error as the judgment and utilizes the time-varying step size. Simulation results demonstrate that the proposed algorithm can improve the convergence speed of constellation points, make the eye opening larger, and the signal noise ratio (SNR) can be increased by 4 dB under the same bit error rate (BER), which is efficient for the recovery of information in high-speed transmission.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-19T03:00:44Z
      DOI: 10.1142/S0217984917400486
       
  • The biospeckle method for early damage detection of fruits
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In the field of fruits damage assessment, biospeckle activity is considered relevant to quality properties of plants, such us damage, aging, or diseases. In this paper, biospeckle technique was applied to identify the early bruising of apples. Then a total of 50 undamaged apples were determined to be artificially bruised as samples. Three methods (Fujii, GD, and LSTCA) were used to extract effective information from these speckle images for measuring the intensity of biospeckle activity. The results showed that for all of three methods, the biospeckle activities of the undamaged areas in apple were similar; after the hit, the damaged area showed a lower biospeckle activity. It can be concluded that early bruising can be identified by biospeckle technique.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-17T08:59:46Z
      DOI: 10.1142/S0217984917400346
       
  • Face recognition algorithm based on Gabor wavelet and locality preserving
           projections
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In order to solve the effects of illumination changes and differences of personal features on the face recognition rate, this paper presents a new face recognition algorithm based on Gabor wavelet and Locality Preserving Projections (LPP). The problem of the Gabor filter banks with high dimensions was solved effectively, and also the shortcoming of the LPP on the light illumination changes was overcome. Firstly, the features of global image information were achieved, which used the good spatial locality and orientation selectivity of Gabor wavelet filters. Then the dimensions were reduced by utilizing the LPP, which well-preserved the local information of the image. The experimental results shown that this algorithm can effectively extract the features relating to facial expressions, attitude and other information. Besides, it can reduce influence of the illumination changes and the differences in personal features effectively, which improves the face recognition rate to 99.2%.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-17T08:59:45Z
      DOI: 10.1142/S0217984917400413
       
  • The study of a novel ultrasonic A-scan signal processing method based on
           fractal theory
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Concerning ultrasonic non-destructive testing of ceramic-lined composite steel pipes, a novel bonding flaw locating method based on fractal dimension is proposed. Ultrasonic A-scan method is used on different positions of the composite steel pipe test piece. The fractal dimension of each curve of ultrasonic vibration signal is calculated. The transformation of each fractal dimension is compared and abnormal positions where bonding defects potentially exist are detected. The result indicates that ultrasonic A-scan signal has an excellent fractal conduct characteristic. It is feasible to compare fractal dimension of signal with the normal range and find out abnormal positions, which can provide basis for follow-up inspections.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T10:49:56Z
      DOI: 10.1142/S0217984917400279
       
  • An improved PolSAR image speckle reduction algorithm based on LMMSE and
           RICA
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Although the linear minimum mean square error (LMMSE) filter removes speckle in polarimetric synthetic aperture radar (PolSAR) images, it has the disadvantage of losing edge detail. In this paper, we propose a new filter based on robust independent component analysis (RICA) and LMMSE. This approach describes edge features in a span image by selecting the adaptive direction window and calculating the edge weight value of the spatial domain, and improves the objective function by using a step polynomial to extract the estimate of the source image with minimum noise. This technique preserves not only the edge information in the images, but also the polarimetric information. Experiments were conducted on the NASA/JPL AIRSAR L-band of the San Francisco area, and evaluated by means of the speckle reduction index and the edge preservation index. The experimental results show that the proposed method effectively reduces speckle, retains edges, and preserves the polarimetric scattering mechanisms.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T10:44:55Z
      DOI: 10.1142/S0217984917400334
       
  • Single image haze removal based on fusion darkness channel prior
    • Abstract: Modern Physics Letters B, Ahead of Print.
      To improve the image quality and compensate deficiencies of haze removal, we presented a novel fusion method. By analyzing the darkness channel of each method, the effective darkness channel model that takes the correlation information of each darkness channel into account was constructed. This method was used to estimate the transmission map of the input image, and refined by the modified guided filter in order to further improve the image quality. Finally, the radiance image was restored by combining the monochrome atmospheric scattering model. Experimental results show that the proposed method not only effectively remove the haze of the image, but also outperform the other haze removal methods.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T10:44:55Z
      DOI: 10.1142/S0217984917400371
       
  • A non-contact method for determining the junction
           temperature of GaN-based blue light LED
    • Abstract: Modern Physics Letters B, Ahead of Print.
      A novel method to determine the junction temperature of GaN type blue light LED based on the spectral parameters is proposed. In this method, the relationships among LED junction temperature, centroid wavelength and FWHM are obtained in the lab, and then the junction temperature of operating LED of the same type can be derived from this relationship. A comparative analysis of the junction temperatures which are measured with the centroid wavelength-FWHM method and with the forward voltage method is performed. The standard deviation between these two methods is found to be about 2.3[math]C. Therefore, the combination of centroid wavelength and FWHM can be used to determine the junction temperature of GaN-based blue LED.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T01:54:08Z
      DOI: 10.1142/S0217984917400231
       
  • Simulation optimizing of n-type HIT solar cells with AFORS-HET
    • Abstract: Modern Physics Letters B, Ahead of Print.
      This paper presents a study of heterojunction with intrinsic thin layer (HIT) solar cells based on n-type silicon substrates by a simulation software AFORS-HET. We have studied the influence of thickness, band gap of intrinsic layer and defect densities of every interface. Details in mechanisms are elaborated as well. The results show that the optimized efficiency reaches more than 23% which may give proper suggestions to practical preparation for HIT solar cells industry.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T01:54:08Z
      DOI: 10.1142/S0217984917400255
       
  • Impacts of road conditions on the energy consumption of electric vehicular
           flow
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In this paper, we use the electricity consumption model for electric vehicular flow [H. Xiao, H. J. Huang and T. Q. Tang, Mod. Phys. Lett. B 30 (2016) 1650325] to study the effects of road conditions on the electricity consumption of electric vehicular flow during the evolutions of shock, rarefaction wave and small perturbation. The numerical results indicate that road conditions have negative influences on the electricity consumption during the evolutions of shock and rarefaction wave (i.e. the electricity consumption increases when road conditions become better) and positive impacts on the electricity consumption during the evolution of small perturbation when the traffic flow is unstable (i.e. the electricity consumption produces oscillation, but its amplitude decreases when road conditions become better).
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T01:54:08Z
      DOI: 10.1142/S0217984917501214
       
  • The simulation of non-Abelian statistics of Majorana fermions in Ising
           chain with Z2 symmetry
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In this paper, we numerically study the non-Abelian statistics of the zero-energy Majorana fermions at the end of Majorana chain and show its application to quantum computing by mapping it to a spin model with special symmetry. In particular, by using transverse-field Ising model with Z2 symmetry, we verify the nontrivial non-Abelian statistics of Majorana fermions. Numerical evidence and comparison in both Majorana representation and spin representation are presented. The degenerate ground states of a symmetry protected spin chain therefore provide a promising platform for topological quantum computation.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T01:54:08Z
      DOI: 10.1142/S0217984917501238
       
  • Chirality-specific lift forces of helix under shear flows
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Chiral objects in a shear flow experience a chirality-specific lift force. Shear flows past helices in low Reynolds number regime are studied by a highly efficient iterative method, based on the analytical solution of a sphere in uniform flow. The chirality-specific lift forces in the vorticity direction experienced by helices are dominated by a set of helix geometry parameters: helix radius ([math]), pitch length (b), number of turns and helix phase angle. Its analytical formula is firstly given. The chirality-specific forces are the physical reasons for the chiral separation of helices in shear flow. Our results are qualitatively in agreement with the simulation results and well supported by the latest experimental observations.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-13T01:54:07Z
      DOI: 10.1142/S0217984917501172
       
  • Low frequency acoustic properties of a honeycomb-silicone rubber acoustic
           metamaterial
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In order to overcome the influence of mass law on traditional acoustic materials and obtain a lightweight thin-layer structure which can effectively isolate the low frequency noises, a honeycomb-silicone rubber acoustic metamaterial was proposed. Experimental results show that the sound transmission loss (STL) of acoustic metamaterial in this paper is greatly higher than that of monolayer silicone rubber metamaterial. Based on the band structure, modal shapes, as well as the sound transmission simulation, the sound insulation mechanism of the designed honeycomb-silicone rubber structure was analyzed from a new perspective, which had been validated experimentally. Side length of honeycomb structure and thickness of the unit structure would affect STL in damping control zone. Relevant conclusions and design method provide a new concept for engineering noise control.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T08:25:55Z
      DOI: 10.1142/S0217984917501184
       
  • Theoretical analysis of a hybrid traffic model accounting for safe
           velocity
    • Abstract: Modern Physics Letters B, Ahead of Print.
      A hybrid traffic-flow model [Wang–Zhou–Yan (WZY) model] is brought out in this paper. In WZY model, the global equilibrium velocity is replaced by the local equilibrium one, which emphasizes that the modification of vehicle velocity is based on the view of safe-driving rather than the global deployment. In the view of safe-driving, the effect of drivers’ estimation is taken into account. Moreover, the linear stability of the traffic model has been performed. Furthermore, in order to test the robustness of the system, the evolvement of the density wave and the velocity wave of the traffic flow has been numerically calculated.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T08:25:49Z
      DOI: 10.1142/S0217984917501044
       
  • Intelligent pulse light source in the performance calibration system of
           two-dimensional neutron detector
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Chinese Spallation Neutron Source (CSNS) project will use numerous two-dimensional (2D) neutron detectors whose ZnS (Ag) scintillator is doped with 6Li. To ensure the consistency of all neutron detectors, a calibration system for the performance of 2D neutron detectors is designed. For radiation protection, the state control of the radiation source gets more and more strict. It is impossible to directly carry out experiments with massive radioactive particles. Thus, the following scheme has been designed. The controlled pulsed laser light source on a 2D mobile platform is used to replace the neutron bombardment to generate the photon. The pulse signal drives the laser diode to generate pulse light. The pulse light source located on the 2D platform is controlled by the core controller, and goes to the wavelength shift fiber through the optical fiber. The host computer (PC) receives the signal from the electronics system, processes data, and automatically calibrates the performance parameters. As shown by the experimental results, the pulse light source can perfectly meet all requirements of 2D neutron detector calibration system.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T08:25:48Z
      DOI: 10.1142/S021798491740022X
       
  • Electrostatic separation for recycling silver, silicon and polyethylene
           terephthalate from waste photovoltaic cells
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Electrostatic separation technology has been proven to be an effective and environmentally friendly way of recycling electronic waste. In this study, this technology was applied to recycle waste solar panels. Mixed particles of silver and polyethylene terephthalate, silicon and polyethylene terephthalate, and silver and silicon were separated with a single-roll-type electrostatic separator. The influence of high voltage level, roll speed, radial position corona electrode and angular position of the corona electrode on the separation efficiency was studied. The experimental data showed that separation of silver/polyethylene terephthalate and silicon/polyethylene terephthalate needed a higher voltage level, while separation of silver and silicon needed a smaller angular position for the corona electrode and a higher roll speed. The change of the high voltage level, roll speed, radial position of the corona electrode, and angular position of the corona electrode has more influence on silicon separation efficiency than silver separation efficiency. An integrated process is proposed using a two-roll-type corona separator for multistage separation of a mixture of these three materials. The separation efficiency for silver and silicon were found to reach 96% and 98%, respectively.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T08:25:48Z
      DOI: 10.1142/S0217984917500877
       
  • Analysis of a novel double driving signal line and driving
           electrodes separated RF MEMS switch
    • Abstract: Modern Physics Letters B, Ahead of Print.
      A novel double driving signal line and driving electrodes separated radio frequency (RF) micro-electromechanical system (MEMS) switch was proposed in this paper to overcome the problems of the high actuation voltage, small displacement, and long pull-down time of the RF MEMS switches. Dynamic equations of the micro beam were built based on the small deflection theory. Dynamic behaviors of the proposed RF MEMS switch were analyzed and calculated by the variable separation method. The effects of different driving voltages, structure parameters and materials on the RF MEMS switch performance were discussed in detail. The simulation results presented that the proposed RF MEMS switch had an actuation voltage of 26 V, a pull-down time of 31.5 [math] and an actuation displacement of 3 [math]. The results also showed that the pull-down time of micro beam increased as the dielectric layer thickness increased. When the beam thickness was higher than 1.1 [math], the switch could not pull down anymore. Additionally, the switch had a lowest pull down time when Al was used as micro beam material, compared to Au, Si, and SiC. The COMSOL Multiphysics finite element analysis was carried out to validate the MATLAB simulation results, and the comparison results were basically consistent with the MATLAB simulation results. Besides, the proposed switch had an insertion loss of −0.2 dB on up-state and isolation of more than −20 dB on down-state at 60 GHz derived from the electromagnetic simulation results. The actuation voltage, pull-down time, actuation displacement, and electromagnetic performances of the proposed RF MEMS switch were compared to some other switches, which were better than some existing switches.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T03:15:28Z
      DOI: 10.1142/S0217984917501135
       
  • Frequency and composition dependency of optical and dielectric properties
           of PMMA/boehmite nano-hybrid prepared via facile aqueous one-pot process
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Optical properties of PMMA/boehmite nano-hybrid synthesized directly from their relevant precursors via facile aqueous one-pot process is studied. Silane coupling agent was applied to make compatible chemically the organic–inorganic counterparts. The chemical bond of SiOAl as the main link between organic and inorganic moieties was confirmed by Fourier transforms infrared (FTIR) spectra. The chemical bond of Si–O–Al as the main link between organic and inorganic moieties. Determining the refractive and absorption index, real and imaginary parts of dielectric constant, energy loss function, and their distribution for PMMA/boehmite nano-hybrid as a function of boehmite loading was assessed in the range of 12–120 THz using FTIR data and Kramers–Kronig relations. The inorganic/organic weight ratio varied from 0.7% to 5% and its impact on optical features was evaluated. It was demonstrated that the optical features of hybrids are frequency-dependent and less affected from boehmite incorporation.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T03:15:26Z
      DOI: 10.1142/S0217984917501202
       
  • Security of a control key in quantum key distribution
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Quantum key distribution (QKD) schemes rely on the randomness to exchange secret keys between two parties. A control key to generate the same (pseudo)-randomness for the key exchanging parties increases the key exchange rate. However, the use of pseudo-randomness where true randomness is required makes a classical system vulnerable to the known plain-text attack. Contrary to the belief of unavailability of this attack in QKD, we show that this attack is actually possible whenever a control key is employed. In this paper, we show that it is possible to make use of the uncertainty principle to not only avoid this attack, but also remove the hazards of photon-number splitting attack in quantum setting. We define the secrecy of control key based on the guessing probability, and propose a scheme to achieve this defined secrecy. We show the general applicability of our framework on the most common QKD schemes.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-11T03:15:25Z
      DOI: 10.1142/S0217984917501196
       
  • Enhanced performance of a structured cyclo olefin
           copolymer-based amorphous silicon solar cell
    • Abstract: Modern Physics Letters B, Ahead of Print.
      The submicron array was fabricated onto a cyclo olefin copolymer (COC) film by a hot embossing method. An amorphous silicon p-i-n junction and transparent conductive layers were then deposited onto it through a plasma enhanced chemical vapor deposition (PECVD) and magnetron sputtering. The efficiency of the fabricated COC-based solar cell was measured and the result demonstrated 18.6% increase of the solar cell efficiency when compared to the sample without array structure. The imprinted polymer solar cells with submicron array indeed increase their efficiency.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-06T05:59:47Z
      DOI: 10.1142/S0217984917400036
       
  • Comparative study of mobility extraction methods in p-type polycrystalline
           silicon thin film transistors
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Channel mobility in the p-type polycrystalline silicon thin film transistors (poly-Si TFTs) is extracted using Hoffman method, linear region transconductance method and multi-frequency C-V method. Due to the non-negligible errors when neglecting the dependence of gate-source voltage on the effective mobility, the extracted mobility results are overestimated using linear region transconductance method and Hoffman method, especially in the lower gate-source voltage region. By considering of the distribution of localized states in the band-gap, the frequency independent capacitance due to localized charges in the sub-gap states and due to channel free electron charges in the conduction band were extracted using multi-frequency C-V method. Therefore, channel mobility was extracted accurately based on the charge transport theory. In addition, the effect of electrical field dependent mobility degradation was also considered in the higher gate-source voltage region. In the end, the extracted mobility results in the poly-Si TFTs using these three methods are compared and analyzed.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:59Z
      DOI: 10.1142/S0217984917400073
       
  • 40 Gbaud binary phase shift keying signal modulation using a substrate
           removed silicon modulator
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Substrate removing technique is proposed in silicon Mach–Zehnder modulator (MZM) to improve the electro-optic bandwidth. Based on this technique, a silicon MZM with 3 dB electro-optical bandwidth of 55 GHz is achieved at 5 V reverse bias for the first time. The V[math] L of the modulator is 1.3 V[math]cm with an on-chip insertion loss of 5.4 dB. The substrate removing technique reduces the electrode transmission loss, achieves the electro-optical group index matching and realizes 50 [math] impedance matching, simultaneously. In this work, we experimentally demonstrate BPSK modulation based on this modulator at the baud rate up to 56 Gb/s.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:58Z
      DOI: 10.1142/S0217984917400097
       
  • Fabricating omnidirectional low-reflection films by nano-imprinting method
           for boosting solar power generation of silicon-based solar cells
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Low-reflection polyethylene terephthalate (PET) films are fabricated with nano-imprinting method. The films are then used to cover polycrystalline silicon solar cells. The morphological and optical properties of films are investigated. The films have periodic cylinder-like nanostructures and relatively low reflectivity in light incident angle ranging from 30[math] to 60[math]. The nanostructures are with a period of 600 nm and height of 90 nm. Besides, the polycrystalline Si solar cells covered with the films exhibit 12% more power generation than the cells covered with glass. Nano-imprinting method offers a cost-effective approach to fabricate omnidirectional anti-reflection films, which could boost the power generation of Si solar cells. Additionally, the films also have potential applications in different types of solar cells due to its facile fabricating process.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:55Z
      DOI: 10.1142/S0217984917400024
       
  • Reliability challenge of ESD protection: From planner SOI MOSFET to SOI
           FinFET
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Implementation of Electrostatic Discharge (ESD) protection in Silicon on Insulator (SOI) technology is a challenge because of the inherent properties of poor heat conductor and heat trapping. In this paper, a novel device as ESD clamp is proposed as Fix-Base SOI FinFET clamp which addresses the troublesome problem of floating base. Moreover, its manufacturing process is compatible to the normal SOI process flow well. Finally, a detailed discussion including current density and thermal distribution are presented with the technique of 3D TCAD simulation.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:54Z
      DOI: 10.1142/S0217984917400048
       
  • The use of double-decker catcher bearing with face-to-face installed inner
           layer bearings
    • Abstract: Modern Physics Letters B, Ahead of Print.
      In active magnetic bearing (AMB) system, the catcher bearings (CB) are indispensable to temporarily support the rotor from directly impacting the stators. In most cases, traditional CB cannot bear the ultra-high speed, vibrations and impacts after a rotor drop event. To address the shortcomings, a double-decker ball bearing (DDBB) with inner two face-to-face angular contact ball bearings are proposed to be used as CB in an AMB system, and the dynamic response of the rotor after a rotor drop event is experimentally analyzed. The results indicate that using a DDBB as a CB helps to reduce the following collision forces after a rotor drop. Larger ball initial contact angles and smaller pre-load force on the inner layer bearings, larger radial clearance of the outer layer bearing and choosing AISI 10AISI 1045 steel which has a larger density for the adapter ring can effectively reduce the maximum impact force after a rotor drop event.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:53Z
      DOI: 10.1142/S0217984917400127
       
  • Analysis of low frequency noise characteristics in p-type
           polycrystalline silicon thin film transistors
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Low frequency noises in the p-type polycrystalline silicon thin film transistors are investigated. It shows a pure 1/f[math] (with [math] near one) noise behavior which can be explained by emission and trapping processes of carriers between trapping states. Subsequently, the gate voltage-dependent drain current noise power spectral densities closely follow the mobility fluctuation model, and the average Hooge’s parameter is then extracted. By considering traditional tunneling processes, the flat-band voltage spectral density is extracted and the concentration of traps in the grain boundary is calculated to be [math]. By converting the frequency to tunneling depth of carriers in the gate oxide, the spatial distribution of gate oxide trapped charges are obtained. Finally, the distribution of localized states in the energy band is extracted. The experimental results show an exponential deep states and tail states distribution in the band gap while [math] is about [math], [math] is [math][math]617 K, [math] is [math] and [math] is [math][math]265 K.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:52Z
      DOI: 10.1142/S0217984917400206
       
  • Dynamic responses of the rotor supported by a new type zero-clearance
           catcher bearing
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Catcher bearings (CB) are required to support the rotor rotating for some time when a failure event of active magnetic bearing (AMB) system occurs. For this purpose, a new type zero-clearance catcher bearing (NTZCB) is proposed. The influences of different parameters of NTZCB on the rotor dynamic responses are theoretically and experimentally analyzed. The results indicate that choosing relatively soft spring and heavy moveable supporting pedestal can effectively buffer the rotor vibrations, which makes it possible for the rotor to keep rotating with the support of the CB system for a long time.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:51Z
      DOI: 10.1142/S0217984917400140
       
  • Anti-reflective microstructure array and its performance evaluation in
           thin film flexible solar cells
    • Abstract: Modern Physics Letters B, Ahead of Print.
      The anti-reflective (AR) structure greatly reduces the light reflection. When it is applied on solar cells, it enables more light to be absorbed by the cells, increasing the energy of the incident light and improving the light-to-electricity conversion efficiency. In this study, the optical properties of AR microstructures are investigated followed by the performance evaluation of solar cells. The AR microstructure is arrayed in a uniform and periodic fashion. When it is applied on PMMA, only 1.0% of the light is reflected away while 2.6% of the light is reflected on glass. The angular dependence performance is also improved with AR structure with 9.4% more light absorption, which can increase the effective energy generation duration for the solar cell. The AR structure is applied to amorphous silicon thin film solar cells by nano-imprinting technology. The solar cell with AR structure gained 8.63% more power compared to the conventional solar cells.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:50Z
      DOI: 10.1142/S0217984917400012
       
  • Aluminum electrolytic capacitors for tablet PC
    • Abstract: Modern Physics Letters B, Ahead of Print.
      Based on the operating conditions of tablet PC, this paper presents the design of a long load life aluminum electrolytic capacitor. Due to the key technology breakthrough of electrolyte with low resistance and excellent temperature stability, the capacitor boasts low leakage current, low impedance, high frequency, high ripple resistance and high temperature resistance. In the meantime, it can pass 5000 h of durability test with load at 105[math]C. The aluminum electrolytic capacitor can be used in tablet PC with long load life.
      Citation: Modern Physics Letters B
      PubDate: 2017-04-05T09:12:50Z
      DOI: 10.1142/S0217984917400115
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.80.29.228
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016