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Differential SAR interferometry (DInSAR) provides a new tool for detecting deformation in the line of sight (LOS) of Earth’s surface. However, not all deformation can be detected. In order to get the maximum detectable deformation, the decorrelation in terms of coherence and deformation has been proposed. The influence of deformation on decorrelation is then discussed for both registering drifted pixels method and registering fixed method. Based on aforementioned analysis, the limitation of maximum detectable deformation has been derived for these two cases. Furthermore, computer simulations are carried out to confirm the detectable deformation discussion as the coherence equals to 0.5. The result of registering drifted pixels method shows that the detectable limitation does not only depend on coherence but also on other factors such as beamwidth. The result of registering fixed pixels method, however, shows that the detectable deformation and baseline have an inverse relationship.

The polar format algorithm (PFA) is a wavenumber domain imaging method for spotlight synthetic aperture radar (SAR). The classic fixed-parameter PFA employs interpolation technique for data correction. However, such an operation will induce heavy computational load and cause degradation in computation precision. To optimize image formation processing performance, this study presents a novel parameter-adjusting PFA, which can implement SAR image formation at an extremely highly squint angle with obviously improved computation efficiency and imaging precision. In the parameter-adjusting PFA, radar parameters, such as center frequency, chirp rate, pulse duration, sampling rate, and pulse repeat frequency (PRF), vary for each azimuth sampling position. Due to the parameter adjusting strategy, the echoed signal can be acquired directly in keystone format with uniformly distributed azimuth intervals. In this case, range interpolation, which is necessary in the fixed-parameter PFA to convert data from polar format to keystone format, can be eliminated. Chirp z-transform (CZT) can be employed to focus SAR data along the azimuth direction. Compared with truncated sinc-interpolation, CZT was found to perform better in inducing less phase and amplitude errors in data processing. When residual video phase (RVP) compensation was accomplished for dechirped signal, the processing steps of the parameter-adjusting PFA were simplified as azimuth CZTs and range inverse fast Fourier transforms (IFFT). Lastly, computer simulation of multiple point targets validated the presented approach.

Speckle noise appearing in the interferometric SAR (InSAR) phase image degrades the quality of interferogram seriously and makes interferogram reflect the scattering characteristics of the target inaccurately, reducing the capability of extracting DEM information of target areas. Therefore, speckle noise reduction plays a major role in InSAR processing by using interferogram filtering. First, according to a terrain model with the assumed geometrical parameters in InSAR system, the paper simulated an interferometric SAR phase image with noise, which can be characterized by the multilook phase distribution based on the circular Gaussian assumption [1]. Second, the paper explores three interferogram filtering algorithm to remove speckle noise: Goldstain filter, Rotating Kernel Transformation and Lee filter; the proper implementation of three methods is given. Last, the paper discusses about the performance comparatively based on experimental results and gives broad conclusions and presents recommendations.

In this paper, single crystal of CuAlNiBe quaternary shape memory alloy was prepared in a high temperature gradient directional solidification furnace with a selective growing crystallizer. And its shape memory performance characters were systematically compared with other series copper base shape memory alloys. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has better shape memory properties.

With Bridgeman directional solidification method the single crystal alloys of CuAl base shape memory alloy (SMA) with different components were prepared. And their shape memory performance characters were systematically investigated. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has much better shape memory properties than that of the CuAlBe and CuAlNi ternary alloy. That meant that in the CuAl base SMA alloy the mixed addition of Be and Ni changed the quenching microstructure has a strengthening effect to improve the shape memory performance of the SMA alloy.

Directional solidification continuous casting (DSCC) processing is steady directional growth process of Cu crystal. It was influenced by seven parameters, and very easy to be broken for some disturbance. Therefore, random crystals grew. In this paper, location of liquid-solid interface Z was set as control object. And correction disturbance closed-loop control was set as general control planning in DSCC processing. Then fuzzy control was selected as control mode. And control algorithm was designed. The closed-loop control process in DSCC processing was simulated. The simulation results showed that control object could return to safe rang even existing random disturbance. And the control process had good stability. Designed fuzzy control device could satisfy DSCC process requirement.

In this paper, single crystal of CuAlNiBe shape memory alloy (SMA) was prepared in a high temperature gradient directional solidification furnace with a selective growing crystallizer. And its performance characters were systematically studied. The results show that the mechanical and shape memory properties of the single crystal of CuAlNiBe SMA alloy has much better than that of the polycrystalline material. This may be explained that the stress concentration at grain boundary caused by the difference of bilateral strains is the dominant reason of deterioration of fatigue properties; therefore single crystal alloy possesses the excellent properties duo to its elimination of grain boundary.

Cardiac catheterization is rarely performed in neonates in China. The medical records of 26 neonates who underwent cardiac catheterization in Shanghai Children's Medical Center from June 1994 to June 2004 were reviewed. These infants weighed 2300 to 4500 g (mean 3 400 +/- 500 g). Postnatal age ranged from 5 to 28 days (mean 15.2 +/- 8.7 days). Right heart ventricle angiography was performed in 24 cases, left heart ventricle angiography in 20 cases and pulmonary angiography in 6 cases. Balloon aortic septostomy (BAS) was performed in 10 cases. Twenty cases were diagnosed with complex cyanotic cardiovascular malformations and 4 with acyanotic heart disease. The implantation of a temporary cardiac pacemaker was performed in 2 cases. All diagnostic and interventional procedures were successfully performed. The catheterization-related complications occurred in 15.3% of the 26 cases, but without mortality. In conclusion, cardiac catheterization is an accurate and safe method for diagnosing complex congenital heart diseases in neonates. Interventional catheterization is useful in the treatment of complex congenital heart malformations.