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The low probability of intercept (LPI) radar waveform is reflected in a lower pulse power and complex structure of the pulse series. The previous one ensures that it avoids being intercepted by the electronic measures system (ESM) carried by the goal; the latter makes it difficult for ESM to separate and identify. As for pulse position jitter pulse array, because of pulse position's random jitter in a specific pulse interval of the pulse repetition interval (PRI), the spectrum broadens and spectral density reduces, making it hard for the ESM to intercept. Meanwhile, because the waveform doesn't have a fixed PRI, it's also difficult to be sorted or identified Therefore pulse position jitter waveform is a rational LPI waveform. Combined with a design about the LPI radar signal waveform, this paper carries out a research on PRI jitter waveform, and provides a waveform generating and echo signal processing method; then the paper simulates the LPI characteristics and comes to a conclusion which has an important applying value .

The fault diagnosis of unmanned aerial vehicle (UAV) flight control system is an important research of UAV in health management. The sensor is the link which easiest to have problems of the flight control system. Making timely and accurate prediction of its faults is particularly important. A strong tracking Kalman Filter method for the sensor fault diagnosis of UAV flight control system was presented in this paper. The parameters of the system were extended to the state variables, the sensor fault observer was constructed, and the joint estimation of states and parameters of flight control system were gotten. The method can be used to real-time estimate the unmeasured states and time-varying parameters. The results of simulation experiments show that the method has a good real-time and accuracy in the sensor fault diagnosis of flight control system.

Taking Jilin province rural areas as an example, according to the local climate, environm- ental conditions and basic load case, designed with independent photovoltaic power generation system, the photovoltaic array Angle, photovoltaic panels, battery, inverter and controller and so on has carried on the optimized selection and design. With professional PVSYST photovoltaic software to design the simulation, to meet user demand and system, battery working status, economic and environmental benefits has made the detailed analysis, for the independent photovoltaic solar power systems in Jilin province to promote the study of theoretical basis.

The paper briefly reviews the domestic and overseas lightning electromagnetic field data acquisition system, and the data transfer rate and data transfer approaches of lightning. Lightning data transfer approaches includes the conventional transmission systems of data collection, and three data transmission means which including the use of power system network to transmit data, the use of the Internet to transmit data and the use of satellite communications to expand the range of distribution.

Wavelength and other factors have a deep influence on temperature measurement system based on CCD image sensor. Deviations between measurement values sometimes are large. In order to reduce error, the temperature outputs in different wavelength combinations do have multi-sensor correlation properties in point of colorimetric temperature measurement system view. The colorimetric temperature measurement algorithm based on real-time adaptive weighted is put forward by such performance index that minimum of standard deviation. According to measured value of each sensor, we will find out the corresponding weights in adaptive manner. And discuss the statistical properties of the estimated standard deviation. Estimation unbiasedness is proved. The algorithm has the following advantages .A much smaller amount of calculation, without any a priori knowledge, only relying on the output of each sensor. All of these make temperature estimation be optimal, measurement accuracy and the real-time performance of the system are improved. Theoretical analysis and experimental results show that the colorimetric temperature measurement algorithm based on the real-time adaptive weighted improves obviously when comparing with the traditional means algorithm in measurement accuracy.

This paper implements Tiger compiler on Hacs language. This compiler is likely to perform many or all of the following operations: lexical analysis, preprocessing, parsing, semantic analysis, and code optimization, target code generation. These are discussed in this paper in detail. As a new design language compiler, Hacs has the prominent advantages of high portability, maintainability and so on .It is easy to achieve.

The extended finite element method is applied to modeling growth of arbitrary crack with crack surface tractions. Firstly, the extended finite element method is investigated for the stress intensity factor solution of surface traction problems. Secondly, for different water pressure acting on the crack surfaces and different crack length, the variation of the stress intensity factors is investigated. Finally, the process of hydraulic fracturing is simulated with the method. Numerical simulations illustrate that the method can effectively model the fracture problems with surface tractions.

In this paper the corrosion inhibition of cetyl trimethyl ammonium bromide (CTAB) combined with sodium silicate on the Q235 and 316L steel were investigated. The results showed that CTAB has a higher corrosion inhibition rate but the cost is higher also. In order to lower the cost, the sodium silicate was combined with CTAB to be corrosion inhibitor. The Results showed that once the CTAB was combined with sodium silicate, there would be a synergistic effect between sodium silicate and CTAB. The corrosion inhibition rate could be greater than 80%. Especially when the concentration ratio of CTAB to sodium silicate was 0.02g/L:2.00g/L, the corrosion inhibition rate for the 316L and Q235 could be up to 87.04% and 91.03% respectively.

In this paper, the hydriding of La (Fe, Fe)₁₃ based alloys was realized by the electrolytic method and the effect of electrolytic temperature on the hydriding was investigated. The phase components and surface morphology were analyzed by XRD and SEM. The magnetic properties of samples were characterized using VSM. Results showed that the electrolytic hydriding process was enhanced by increasing the electrolytic temperature. The Curie temperature was increased from 196 K to 325 K. Through Arrot-plot analyses, it was found that the phase transition of samples tends to be a second order phase transition. The magnetic entropy change was reduced from 8.03 J/(kg•K) to 2.03 J/(kg•K) under a maximum external field of 1.5 T.

Based on uniform design, finite element simulation of dieless tube hydroforming and double-screening stepwise regression method, a many-to-many polynomial regression equation set was established, whose independent variables are time t₁ at which axial compression displacement from 0 reaches 25mm and time t₂ at which internal pressure from 0 achieves 65MPa in 60 seconds, while dependent variables are hoop plastic strain s₁₁ and radial plastic strain s₂₂ in the midmost position of hydroformed tube. Analysis of partial correlation coefficient indicates that the effect of t₂ on s₁₁ is a little stronger than t₁ and there is no interaction between t₁ and t₂ on s₁₁, while s₂₂ is influenced by t₂² and t₁t₂². The many-to-many regression model not only quantificationally describes the action of loading factors on plastic strains but also reflects the inherent relevance between plastic strains, which is more useful than several one-to-many regression models to solve problems such as loading characteristic analysis, loading parameters design and optimization, etc.