Advanced Materials Research Vols. 301-303

Abstract: The spreading resistance is a very important parameter in the applications of heat sink. The design of electronic devices will fail without considering the influence of the spreading resistance. In this paper, a simple thermal model was simulated by Computational Fluid Dynamics software. Some factors, which have great influence on the spreading resistance, have been analyzed. The spreading resistance decreases significantly with the increasing of the area ratio between the heat source and the base-plate. While the ratio being 1, the spreading resistance reaches the mix value. The greater the thermal conductivity of heat sink, the lower the spreading resistance. With the increasing of the thickness of base-plate, the spreading resistance reduces. However, if the thickness exceeds the critical value, the spreading resistance will increase. And the spreading resistance reaches the mix value while the centers of heat source and the base-plate are overlapped.

Abstract: The ionic liquid is a green solvent and catalyst, its application is abroad. By using at density functional theory (DFT) at B3LYP/6-31G* levels, The N-ethyl morpholinium ionic liquid with different alkyl length have been studied. The computed results indicate that the ionic liquid formed by ethyl N-ethyl morpholinium and a chlorine ion has nine structures and eighteen positions. Three hydrogen bonds have been formed in each position, the hydrogen bond between chlorine ion and hydrogen atom in morpholinium ring is strongest and shortest. The hydrogen bond between chlorine ion and hydrogen atom in ethyl is weaker, which can strengthen the stability of ion pair. The nine structures of the ionic liquid formed by ethyl N-ethyl morpholinium and a chlorine ion are compared, the ionic liquid of MO1,2NC和MO1,2LC is more stable, the energy released of MO1,2LC is biggest, the energy released of MO1,2NB is smallest. For ethyl N-ethyl morpholinium, propyl N-ethyl morpholinium and butyl N-ethyl morpholinium, as the alkyl length becomes longer, the binding energy between chlorine ion and morpholinium with different alkyl length becomes weaker.

Abstract: Radial velocity error of the spectra always be given by the widths of the cross-correlation function of the target spectrum and template spectrum. Radial velocity error affected by many inevitable factors, caused by instrument, observation weather, etc.. Another important error comes from calibration, which should be reduced as much as possible. This paper analysis the error based on different temperatures for different types of spectral. The effect of the calibration error to the radial velocity error is also presented.

Abstract: It is described that the acceleration signal is modulated to optical phase by Micheson interference device and demodulated by Synthetic-heterodyne signal demodulation(SHSD) ,when the error is compensated by alternating current phase tracking homodyne compensation scheme (PTAC). Then the digital signal proseccing system is designed with SOPC technology. And DSP and intelligent data communication interface run in parallel . The experiment has shown that when the virtual value of external acceleration signal is constant, in selected working frequency range, the system output signal can trace the vibration acceleration signal linearly and reliably.

Abstract: A novel faint signal processing method based on phase-lock amplification principle is developed to enhance the sensitivity of pump/probe-based laser generated and laser detected surface acoustic waves (LG/LD SAW) spectroscopy system. This novel method involves a “dead zone” filter located before a common phase-lock amplification unit, which wipes off most of the noise stacked on SAW signal. This paper explored the working principle of this novel signal processing method based on the knowledge of the characteristics of the system noise and the signal. The experiment result shows that the detection system’s sensitivity has been dramatically improved by this new signal processing method.

Abstract: A novel DNA biosensor system on silica microspheres as solid carriers which based on the fluorescence resonance energy transfer (FRET) was presented in this work when CdTe quantum dots (QDs) were as energy donors and Au nanoparticles (AuNPs) were as energy accepters. Compared with the fluorescent intensity of CdTe QDs, the fluorescent intensity of DNA biosensors decreased extremely, which indicated that the FRET occurred between CdTe QDs and AuNPs. The biosensor system would have a certain degree recovery of fluorescence when the complementary single stranded DNA was introduced into this system. The DNA detection results indicated that this novel fluorescent DNA probe system could recognize the existence of complementary target DNA or not.

Abstract: Vision for navigation had been an active area of research for more than three decades, and a vision-based navigation system always needs real-time image collecting and processing to acquire navigation information. In the indoor scenarios, illuminant reflection is often found in navigation images because of smooth surfaces in the environment, such as marble floor, planes of furniture and etc. The negative effect of illuminant reflection in navigation images is obvious and might lower the performance of the navigation system, As to resolve the above problem, the issue of how to detect illuminant reflection should be considered, This paper proposed an automatic detection algorithm to segment illuminant reflection regions in a color image using saturation and brightness characteristics as well as the brightness distribution of the illuminant reflective regions. As to verify the robustness and accuracy of this algorithm, experiments were carried out in different indoor environments where illuminant reflection is found in navigation images, the experiments results we obtained indicated that this algorithm is sufficient to handle the problem with providing good detection results as expected.

Abstract: The main content of this paper is to conduct the structure design of the surface AR coating used to improve the LED luminous efficiency, and study the different structural parameters of AR coating under different circumstances. Use transfer matrix method to simulate and calculate the optical character of different surface structures of AlGaInP LED, and then carry out the simulation on the data. Besides, it also considers the impact of gradient layer on the transmission rate of film and designs the parameters that are close to the experimental conditions.

Abstract: The application of electrochemical techniques for DNA detection is motivated by their potential to detect hybridization events in a more rapid, simplistic and cost-effective manner compared to conventional methods. Here, we present an electrochemical DNA biosensor for the specific and quantitative detection of single-stranded DNA (ssDNA). Probe oligonucleotides were immobilized onto gold electrodes by a 5′ end thiol-group linker. Following hybridization with the complementary DNA, the cobalt complex was electrochemically accumulated on the double-stranded DNA layer and the differential pulse voltammogram (DPV) for this electrode gave an electrochemical signal due to the redox reaction of [Co(phen)₃]²⁺/³⁺ that was bound to the double-stranded DNA on the electrode, and it can sense single base-pair mismatche within the sequence of the hybridized double-stranded DNA (dsDNA).

Abstract: The low beam light optical configuration of high brightness LED headlamp is designed in this paper. When we design low beam light, three same optical units are overlapped to achieve sufficient luminous flux. LED optical source is arranged and packaged into a LED by using multi-chip in linear array. Each unit uses multi-ellipsoid reflector to converge light issued by multi-chip high-power LED light source, which covers partial light to form by light-dark blocking some of the light baffle to form an cut-line, the light is converged through optical lens to obtain the light-type that low beam light requires. The application of ASAP software implements the simulation, and the test results show that this design meets the national standard of low beam light.