Abstract:The effects of background millimeter radiations (BMR) in patients with coronary artery disease (CAD), hypertension and in subjects with Inherited real risk of CAD, were investigated through invariant statistic measures, typical of nonlinear dynamics analysis of biological systems. The experimental evidences show that BMR ameliorate the nonlinear complexity in biosystems, recognized sign of physiological behavior, by increasing both the rate of unpredictability of heart rate variability (HRV) in patients with metabolic syndrome and the fractal dimension of coronary microvessel oscillations in subjects with pre-metabolic syndrome, healing their genetic alteration and CAD Inherited real risk.

Abstract:The BixFeO3 films (0.80≤x≤ 1.20) were prepared by sol-gel technique on Si substrates. Effects of x variation on microstructures and optical properties of the BixFeO3 films are reported. It is shown that in the films with both insufficient and excess bismuth dosage, impurity phases such as Bi2Fe4O9 and iron oxide appeared. Raman spectra of the films were presented in the spectral range of 50~800cm-1. The refractive index (n) of the films decreases with increasing x at wavelength lower than 600nm, the extinction coefficients (k) of all films were comparable. The bandgaps of the films changed from 2.65eV to 2.76eV.

Abstract:Using full-vectorial, three dimensional, finite difference time domain (FDTD) simulator, greatly enhanced extraordinary optical transmission (EOT) is studied in a composite metal system, which is constructed by stacking a hexangular annular ring array over a hexangular hole array, perforated in a metallic film. In comparison with conventional periodic hole array, perforated in a single metal film, the composite metal system exhibits much stronger transmission amplitude and narrower band width. Such a novel behavior of EOT is well explained by the numerical results obtained from the distributions of electric field intensity, flowing maps of Poynting vectors and frequency dispersions. The results show that strongly excited surface plasmon polaritons (SPP) plays a dominant role in coupling light throughout the composite system.

Abstract:A near-infrared (NIR) organic light-emitting devices (OLEDs) was demonstrated with emissive layers (EMLs) based on erbium (111) tris(8-hydroxyquinoline) (ErQ) and the blue host material of 9,10-di-beta-naphthylanthraeene (ADN). The fundamental structure of the devices is (p-Si /NPB /EML /Bphen /Bphen:Cs2CO3 /Sm /Au), where three sets of EMLs (ErQ/ADN bilayer, (ErQ /ADN)×3 multilayer, and ErQ: ADN doped layer) have been compared. In all the three structures, 1.54 μm electroluminescence was observed due to the 4I13/2~4I15/2 transitions of Er3 . Compared with the ADN/ErQ bilayer structure, the NIR electroluminescence (EL) intensity is stronger by three times in the ADN: ErQ(1∶1) doped structure. The ADN: ErQ composite films with different doping levels were further characterized by the measurements of absorption, photoluminescence and photoluminescence decay time. The results indicate effective energy transfer from ADN host to emissive molecular ErQ in the NIR EL process.

Abstract:An experimental study of two photon absorption(TPA) in the HgCdTe pn junction detectors was reported. The excitation light source was a picosecond pulsed infrared laser. Even the incident photon energy was about 60% of HgCdTe(MCT) bandgap, an obviously photo-response was still observed. Quantification dependence of the peak amplitude on the incident intensity presented a slope of 2 by linear fitting to the experimental data in log-log coordinate, which indicated that the photo-response exhibited a quadratic power dependence on the incident intensity, suggesting a typical TPA process. The two photon absorption coefficient(TPAC) inside the space charge region(SCR) is as high as 130 times that of outside the depletion region which can be attributed to the TPA Franz-keldysh effect.

Abstract:Cadmium sulfide thin films were grown on transparent conductive oxide coated glass substrates by radio frequency magnetron sputtering with a substrate temperature ranging from 30℃ to 200℃. X-ray diffraction measurements reveal that cadmium sulfide films were polycrystalline with the hexagonal wurtzite structure. The scanning electron microscope images show a good crystalline quality of the films which can also be confirmed by the Raman spectra, ultraviolet-visible absorption spectra and the photoluminescence spectroscopy. The Raman spectra measurements indicate that the compressive stress in the CdS films increases with increasing growth temperature.

Abstract:A simple and cost effective method to fabricate column shape two dimensional photonic crystals by holographic lithography technique using double development has been reported. In the process two dimensional big-dot-type periodic structures have been generated directly on positive photoresist, and then transferred to the substrate through the Si3N4 hard mask. By using double development, the photoresist exposed to high and medium intensity can be developed away effectively, while those exposed to low intensity can still be preserved. The period of the two dimensional structures can be easily controlled by adjusting the angle of two incident beams. The structures in a large period range over a relative large area have been generated with good uniformity and reproducibility. The processing parameters are discussed in detail.

Abstract:By using infrared detector and readout circuit, an uncooled infrared detecting system was developed. The detector using diode as the temperature sensor is compatible with integrated circuit process. A new device structure was used to improve the fill-factor from 20% to 80%. The area of micromachined structure is 35μm×35μm. The offset voltage of the readout circuit is 3μV. The output noise of the detector is 2μV. The responsivity of the detector is 7894.7V/W, specific detectivity of the detector is 1.56×109cmHz1/2/W, noise equivalent temperature difference of the detector is 330mK, and response time of the detector is 27 ms.

Abstract:Some key issues associated with the interaction efficiency of a harmonic gyrotron oscillator operating in the millimeter wave regions were studied. Operating at the third-harmonic, the required magnetic field was reduced to 1.185 T for a 94GHz gyrotron oscillator, which makes it possible to replace the superconducting magnet by a permanent magnet. A self-consistent code and a particle-in-cell(PIC) software were used to investigate the harmonic beam-wave interaction. The interplay between the cavity quality factor and interaction efficiency was revealed, and the dependence of both beam voltage and electron beam pitch factor on the coupling coefficient was also studied. Through carefully choosing operating mode, optimizing system parameters, and using linearly increased axial magnetic field, the output power of 95kW and efficiency of 19.7% was achieved under accelerating voltage of 40kV, beam current of 12 A, and transverse velocity spread of 3%. The efficiency can be further increased to 39. 2% by utilizing a single stage depressed collector(SDC).

Abstract:A simple method based on the physical characteristics to get the main parameters of folded waveguide traveling wave tube (TWT) circuit is presented. Providing the operating frequency and beam voltage, the authors can obtain the initial structural parameters of the FWTWT. A D-band folded waveguide circuit was used to verify this method. The cold characteristics including dispersion relation and interaction impedance were analyzed. The simulation results show good agreement with their theory formula analysis. The folded waveguide slow-wave structure has flat dispersion relation, fairly high interaction impedance about 3.5 ohms at the center frequency of 220GHz. The large signal performance of 27mm (50 periods) folded waveguide circuit was predicted. Simulations show the nonlinear gain is 13.5dB at 220GHz where beam voltage and current are 20.6kV and 15mA, respectively. A saturated 3dB bandwidth is 11GHz (213~224GHz). The Microfabrication process to produce the folded waveguide circuits was discussed. The first example of the folded waveguide circuit was fabricated by UV-LIGA process.

Abstract:The MWIR continuous zoom optical system has many advantages. A method for designing the system with large zoom range was introduced. Then, a system with 8 lenses was designed. The system works in the wavelength range of 3.7~4.8μm with 10~450mm continuous zoom, and the MTF value in Nyquist limit (16lp/mm) is more than 0.3 over the full range. The F/number of the system is 4. It can satisfy 100% cold shield efficiency.

Abstract:A semi-analytical small signal parameter extraction method for high electron-mobility transistor(HEMT) under different bias conditions is presented. Based on test structure to determine the pad capacitance and parasitic inductances, the semi-analysis method is used to extract parasitic resistances and to improve the precision of the parasitic resistance in the small signal model. The agreement between the measured S-parameters and simulated ones is excellent over the frequency range up to 40GHz under multibias condition.

Abstract:In this paper, a novel graph matching algorithm, called Filtering Bi-directional K-Nearest-Neighbors Strategy (Filtering BiKNN Strategy) is presented to solve the pseudo isomorphic graph matching for remote sensing images with large affine transformation, similar patterns or from multisource sensors. BiKNN was proposed to describe the adjacent relationships of feature points. Filtering strategy is used to eliminate dubious matches of pseudo isomorphism for restrict constraints. Any BiKNN vertices of candidate outliers treated as outliers in latter iterations are rechecked with the expanded BiKNN respectively. Candidate outliers with stable graph structures are recovered to the residual sets. Three typical remote sensing images and twenty image pairs were utilized to evaluate the performance. Compared with random sample consensus (RANSAC), graphing transformation matching (GTM) and the proposed BiKNN matching, Filtering BiKNN Strategy can deal with pseudo isomorphism and obtain the highest recall and precision.

Abstract:With the high accuracy of the stellar angular positions, the camera calibration with the night sky observation is available and indispensable. In order to estimate the camera parameters even with higher order nonlinear distortions, a two-step model and the corresponding iterative optimization based on the invariability of inter-star angle were developed in this paper. Furthermore, a compact recursive average filter was designed to improve the accuracy while not adding significantly computation time. The experimental results demonstrated that the proposed model can implement star tracker camera calibration with higher accuracy than the known method.

Abstract:A novel approach to the problem of visible and infrared automatic image registration was proposed. The registration is performed by extracting affine covariant regions through same level extremal region (SLER) detector on a gray gradient image. Then, hypergraph matching algorithm was employed to obtain identical key points. The approach is especially suitable for registering multi-sensor infrared images where the quality of images or the corresponding edge maps are worse than the counterparts on a common optical image. Experiments performed on several challenging real image pair show that our proposed method achieves better performance than other approaches.

Abstract:This paper proposed a novel adaptive regularization super-resolution (SR) method. The regularization term only penalizes the low-frequency components in the image. Meanwhile it protects the high-frequency components which may represent edge, in which the penalty threshold is automatically determined based on a linear function. For the selection of regularization parameter, a logarithmic function is proposed to adaptively determine the optimum regularization parameter in each iteration step instead of a constant regularization parameter. The proposed algorithm has been tested in the synthetic visiblelight image sequence and real infrared images. Experimental results show that the proposed approach is robust and can restore image details efficiently.

Abstract:The level set based active contour model (LSAC) has been proved advantageous for image segmentation. Based on LSAC techniques, a novel algorithm was proposed to overcome the difficulties of image segmentation in infrared human detection systems. It consists of a motion-based LSAC module, a threshold-based LSAC module and a fusion module. The motion-based LSAC, which bridges level set and background-subtraction techniques, conducts foreground segmentation and background estimation simultaneously based on converged level set functions. It works for detecting the moving regions in a sequence. Moreover, its output is regarded as the input of the threshold-based LSAC, which combines level set and thresholding techniques. This threshold-based LSAC module has the ability to extract the image regions having intensities within the range specified by dual thresholds and works for detecting all possible regions that may contain human candidates. Finally, the third module fuses the LSAC outputs and results in faithful segmentation result owing to the morphological open reconstruction. Furthermore, the fast numeric scheme proposed for evolving the LSAC modules and the optimized algorithmic flow improves efficiency. Experimental results demonstrate that the algorithm enjoys better performance in accuracy, efficiency and robustness to camera movement and temporal changes in the scene in comparison with the rival algorithms.