- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Study of the IR Spectra of the Saliva of Cancer Patients
摘要： Feasibility has been demonstrated in principle for the diagnosis of lung and breast cancer by subjecting saliva to Fourier transform IR spectroscopy. Statistically significant differences in the saliva of lung cancer patients are seen at 1070–1240 cm–1, while significant differences are seen throughout the entire range for breast cancer patients. The I1398/1454 and I1240/1310 ratios were determined and found to be statistically reliable for detecting cancer pathology. Correlations were found for the intensities of the absorption bands in these IR spectra with nonspecific biochemical saliva parameters, which generally characterize greater intoxication as well as suppression of the systems for antioxidant protection and the immune response. A promising research trend involves the use of the IR spectroscopy of saliva for monitoring treatment and cancer recurrence.
关键词： Fourier transform IR spectroscopy,saliva,diagnostics,oncology
更新于2025-09-19 17:15:36
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Method of correcting stitching errors in reconstructing a synthetic-aperture digital hologram with seams
摘要： We propose a correction method based on the shift theorem of the Fourier transform for the non-integer pixel stitching error in a synthetic-aperture digital hologram with seams. After being Fourier transformed, the sub-holograms stemming from the dislocated recording planes are multiplied by a phase factor and then superposed onto in-place sub-holograms. Finally, the entire hologram is inverse Fourier transformed for reconstruction. This method is applied to simulated particle detection. The results show that the correlation coefficient (CC) between the reconstructed image and the simulated target image is 1.5 times, by comparison with an image that does not involve the phase-factor correction, and particles at the seams are clearly visible. In addition, the effect of noise on the method is small. These verify the feasibility of the method.
关键词： phase factor,shift theorem of the Fourier transform,synthetic-apertures,Stitching errors,non-integer pixel
更新于2025-09-19 17:15:36
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Enhanced Optical Communications Through Joint Time-Frequency Multiplexing Strategies
摘要： We present a power-efficient and reduced-complexity all-optical approach to generate high-bit rate superchannels, based on joint time-frequency multiplexing. Both optical orthogonal frequency division multiplexing (OFDM) and Nyquist-optical time division multiplexing (N-OTDM) signals are generated and processed using a wavelength-selective switch (WSS). We use the fractional Fourier transform (FrFT) to introduce the largest degree of flexibility in optical networking, and we experimentally demonstrate that the transmitted signal can be received either in parallel, as OFDM subcarriers, or in series, as an N-OTDM signal. Compared to conventional optical OFDM, we achieve peak to average power ratio (PAPR) flexible reduction; compared to N-OTDM, we introduce chromatic dispersion (CD) management. We successfully demonstrate a field trial experiment of 4-channel 40 Gb/s hybrid OFDM/N-OTDM transmission over the 89.2-km Japan gigabit network-extreme (JGN X) test bed, with 1 bit/s/Hz spectral efficiency.
关键词： optical Fourier transform,optical signal processing,Nyquist OTDM,OFDM,fractional Fourier transform
更新于2025-09-19 17:13:59
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Generation and pulsating behaviors of loosely bound solitons in a passively mode-locked fiber laser
摘要： We demonstrate the experimental observation of loosely bound solitons and pulsations in a passively mode-locked ?ber laser. The soliton amount inside one soliton bunch typically increases with the increment of pump power, while the average pulse-to-pulse separation in the regime of hundreds of picoseconds decreases in principle accordingly. Besides, by employing the real-time measurement based on the dispersive Fourier-transform technique, we ?nd that some solitons in a single bunch are experiencing a simultaneous pulsating process with a period corresponding to 100 times longer than the cavity round-trip time. The experimental results can be bene?cial for better understanding the formation of multiple solitons and pulsating solitons and enriching the nonlinear phenomena in complex soliton systems.
关键词： dispersive Fourier-transform technique,pulsating solitons,loosely bound solitons,passively mode-locked ?ber laser
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - Nashville, TN, USA (2019.11.3-2019.11.6)] 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - Over 70-GHz 4.9-V <sub/>ppdiff</sub> InP linear driver for next generation coherent optical communications
摘要： We propose a multichannel random discrete fractional Fourier transform (MRFrFT) with random weighting coefficients and partial transform kernel functions. First, the weighting coefficients of each channel are randomized. Then, the kernel functions, selected based on a choice scheme, are randomized using a group of random phase-only masks (RPOMs). The proposed MRFrFT can be carried out both electronically and optically, and its main features and properties have been given. Numerical simulation about one-dimensional signal demonstrates that the MRFrFT has an important feature that the magnitude and phase of its output are both random. Moreover, the MRFrFT of two-dimensional image can be viewed as a security enhanced image encryption scheme due to the large key space and the sensitivity to the private keys.
关键词： fractional Fourier transform,image encryption,Chaotic logistic map,random phase mask
更新于2025-09-19 17:13:59
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A Non-Isolated Buck-Boost DC-DC Converter with Continuous Input Current for Photovoltaic Applications
摘要： High-power grinding mills are used in the cement and mining industries to crush clinker or copper ore and grind these materials to fine powder. The multi-megawatt speed-controlled mill drives operate at a very low angular speed. Synchronous motors with a high number of pole pairs are used as the prime movers. They are traditionally fed by load-commutated thyristorized cycloconverters. These are prone to failure modes that can lead to excessive torque pulsations and high overcurrents. The huge stator, which was built as a separate ring-shaped structure around the tubular mill, may then get mechanically displaced, and the operation of the plant is interrupted. A novel and reliable direct drive uses a voltage source inverter that operates at the unity power factor for increased efficiency. Synchronous optimal pulsewidth modulation ensures a low harmonic current distortion and reduced switching losses at a very low switching frequency. The optimization of the pulse patterns takes the anisotropic magnetic properties of a separately excited synchronous motor into account. The implementation in a 23-MW semiautonomous grinding mill installed in a Zambian copper mine is intended.
关键词： Alternators,pulse width modulation inverters,gradient methods,ball milling,software algorithms,variable speed drives,Fourier transform
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Sustainable Power and Energy Conference (iSPEC) - Beijing, China (2019.11.21-2019.11.23)] 2019 IEEE Sustainable Power and Energy Conference (iSPEC) - Analysis on Load Characteristics of Distributed Photovoltaic Access to EVs industry
摘要： In this communication, the computation of the perturbation-based electric field integral equation of the form Rn?1, n = 0, 1, 2, . . . , is accelerated by using fast Fourier transform (FFT) technique. As an effective solution of the low-frequency problem, the perturbation method employs the Taylor expansion of the scalar Green’s function in free space. However, multiple impedance matrices have to be solved frequency orders, and the computational cost becomes at different extremely high, especially for large-scale problems. Since the perturbed kernels still satisfy Toeplitz property on the uniform Cartesian grid, incorporated the FFT based on Lagrange interpolation can be well to accelerate the multiple matrix vector products. Because of the nonsingularity property of high-order kernels when n ≥ 1, we do not need to do any near field amendment. Finally, the efficiency of the proposed method is validated in an iterative solver with numerical examples.
关键词： perturbation method,integral equation (IE),Fast Fourier transform (FFT),low frequency
更新于2025-09-19 17:13:59
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EXPRESS: A Study of the Surface of Fe <sub/>3</sub> O <sub/>4</sub> @SiO <sub/>2</sub> Nanoparticles Functionalized with Different Groups Using a Photoacoustic Infrared Spectroscopic Method
摘要： A permanent development of hybrid materials based on the highly absorptive or opaque materials has prompted a need of analytical tools, which are able to overcome obstacles connected with their physicochemical features. Iron oxide (II, III) (Fe3O4) nanoparticles gained a huge attention as supporters, as they are not only easily accessible using various synthetic approaches, but they also exhibit homogeneity and paramagnetic properties, which make them easily separable materials. Nevertheless, the classic infrared spectroscopic studies might meet several problems with characterization of such systems. Therefore, infrared spectroscopy in photoacoustic mode using Fourier transform infrared–photoacoustic infrared spectroscopy (FT-IR PAS) can be an extremely sensitive and exact analytical tool for investigation of the magnetite-based hybrid materials surface. Herein, we present a synthesis of Fe3O4 nanoparticles using co-precipitation method with their subsequent encapsulation within silica matrix decorated with different silanes containing various terminal functional groups. The proper syntheses of core/shell structures were confirmed using the FT-IR PAS method. Each spectrum exhibited specific bands corresponding to vibrations of magnetite particles, silica lattice and particular surface functional groups, which strictly indicated successful grafting of silanes onto Fe3O4 surface.
关键词： PAS,Magnetite nanoparticles,Fourier transform infrared,core/shell structures,surface analysis,photoacoustic infrared spectroscopy,FT-IR PAS,FT-IR
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Chongqing, China (2019.10.11-2019.10.13)] 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Research on Control algorithm of Photovoltaic Grid-connected Inverter Based on Fuzzy Logic
摘要： In this communication, the computation of the perturbation-based electric field integral equation of the form Rn?1, n = 0, 1, 2, . . . , is accelerated by using fast Fourier transform (FFT) technique. As an effective solution of the low-frequency problem, the perturbation method employs the Taylor expansion of the scalar Green’s function in free space. However, multiple impedance matrices have to be solved frequency orders, and the computational cost becomes at different extremely high, especially for large-scale problems. Since the perturbed kernels still satisfy Toeplitz property on the uniform Cartesian grid, incorporated the FFT based on Lagrange interpolation can be well to accelerate the multiple matrix vector products. Because of the nonsingularity property of high-order kernels when n ≥ 1, we do not need to do any near field amendment. Finally, the efficiency of the proposed method is validated in an iterative solver with numerical examples.
关键词： integral equation (IE),perturbation method,Fast Fourier transform (FFT),low frequency
更新于2025-09-19 17:13:59
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On the Problem of Taking into Account the Effect of Meteorological Factors on Large Precision Systems: A Case Study of the Baksan Large-Base Laser Interferometer
摘要： Variations in ambient temperature and atmospheric pressure coincide with the wave train of the lunar–solar tide in the diurnal and semidiurnal frequency ranges, where they have the greatest influence on deformation measurements by laser interferometers. Based on data from the Baksan laser interferometer of the Sternberg Astronomical Institute of Moscow University over a 15-year observation period, it is shown that the response of large measuring systems to these variations has a pronounced frequency dependence. Using the constructed mathematical model the problem of taking into account how meteorological factors influence measurements is solved in the frequency domain with the aid of images of deformation time series and meteorological factors, obtained by Fourier transform. A transient function is constructed in the form of the so-called aperiodic link, which takes into account the frequency dependence and delay of thermoelastic deformation of the measuring system on the variation in ambient temperature. The converted temperature and pressure images are subtracted from the deformation image using the corresponding transient functions. As a result, the new deformation image bears virtually no influence of meteorological factors; inverse transform yields a new deformation time series.
关键词： deformation of the lithosphere,Fourier transform,lunar–solar tide
更新于2025-09-19 17:13:59