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The imaging methods and results for biological materials by scanning electron acoustic microscopy (SEAM) have been introduced in this paper. The images of the amplitude and phase of a plant leaf by SEAM show that the amplitude image involves more surface features but the phase image displays more subsurface structures. The laminated imaging experiments, which use the x- and y-components of SEAM signals with different reference phases, show the subsurface structures in different depths of biological materials, such as, plant leafs, biological tissues, etc. Using a photothermal technique, the thermal diffusion lengths of the samples of biological materials can be evaluated, by which the depths of the subsurface structures in the laminated images can be estimated. In addition, the damage areas of the leaf and muscles are also imaged by SEAM. For comparison, the second electron images of the same areas of the samples studied by SEAM are also obtained. The images show that SEAM is sensitive to micro-structures of surface, and also subsurface, structures of biological materials.

To investigate the effects of TNF-alpha, TNF-beta and the acceptor expression about mechanical renal trauma with extraneous ADM.There were 104 healthy adult plain grade Wistar rat, randomly divided into four groups:8 in the group of control, 32 in the group of trauma, 32 in the group injected ADM before trauma, 32 in the group injected ADM post trauma. The experimental model of rat kidney with mechanical trauma was prepared by striking the area of rat skin reflecting by kidney with free dropping ferrous hammer in the last three groups. ADM (0.1 nmol/kg) administrated by intraperitoneal injection at 10 minutes before trauma or post trauma respectively in injected groups. All rats were executed by drawing-out all the blood in their hearts. Renal tissue was investigated to study positive expression of TNF-alpha, TNF-beta, TNFR after SABC stained.TNF-alpha expression:the TNF-alpha expression of trauma group was more positive than it of control group in the wound early time. The expression of group injected post trauma was less than it of trauma group at 1 h (P0.01). The expression of group injected before trauma was less than it of trauma group at 6 h (P0.05) TNF-beta expression: the TNF-beta expression of trauma group was less than it of control group at 1 h and 6 h (P0.05). The TNF-beta expression of group injected post trauma was more positive than it of trauma group at the same time of 1 h and 6 h (P0.01). TNFR expression: the TNFR expression of trauma group was less than it of control group at 6 h (P0.01). The TNFR expression of group injected before trauma was more positive than it of trauma group in the at the same time of 1 h and 6 h (P0.01).The TNFR can regulate the TNF-alpha and the TNF-beta in dynamic balancing. The regulation of TNFR is main to TNF-alpha. What the TNF-beta participated in renal trauma mainly is the anti-damage process. ADM can reduce the expression of TNF-alpha. ADM increases the expression of TNF-beta and TNFR.

The principle of a new large-aperture high-accuracy interferometer for flow visualization is presented. The interferometer uses a Twyman-Green interferometer as a beam-splitter, a grating as a detector, and a real-time moire fringe method to eliminate systematic errors. The interferometer has been used to measure the flow fields in a shock tunnel and obtained satisfactory results.

In this paper an algorithm of rapid fringe thinning is presented. It consists of fringe smoothing and skeleton extracting. The pulsed noise and `barr' in the fringes can be restrained effectively and the `hole' in the fringes can be padded. Some applications of the method to interferograms of explosive flow field and hypersonic shock tunnel flow field are also presented.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes the methods of extracting shock wavefront deleting fringes from the interferograms of transient flow field and registering time series shock wavefront on a single image. These methods have been used to extract and register time-series shock wavefront from the interferograms of explosive flow field and muzzle flow field and to calculate the propagation velocity of the shock wavefront.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, a hybrid system of optics and computer for 3D object recognition is presented. The system consists of a Twyman-Green interferometer, a He-Ne laser, a computer, a TV camera, and an image processor. The structured light produced by a Twyman-Green interferometer is split in and illuminates objects in two directions at the same time. Moire contour is formed on the surface of object. In order to delete unwanted patterns in moire contour, we don't utilize the moire contour on the surface of object. We place a TV camera in the middle of the angle between two illuminating directions and take two groups of deformed fringes on the surface of objects. Two groups of deformed fringes are processed using the digital image processing system controlled and operated by XOR logic in the computer, moire fringes are then extracted from the complicated environment. 3D coordinates of points of the object are obtained after moire fringe is followed, and points belonging to the same fringe are given the same altitude. The object is described by its projected drawings in three coordinate planes. The projected drawings in three coordinate planes of the known objects are stored in the library of judgment. The object can be recognized by inquiring the library of judgment.

This paper presents the interference measurement of the boundary layer in hypersonic shock tunnel with a new large aperture, high sensitive moire interferometer. The principle of the interferometer is presented. This paper shows that the conjugate relation between the model in the tunnel and the observing plate can eliminate the diffracting affection due to the model and therefore the boundary layer can be visualized. The moire interferograms of the boundary were processed with computer digital image process technique. From the deformation of moire fringe, the density profile is presented.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper presented the measurement of the exhaust plume field of solid rocket with a moire interferometer. The principle of the moire interferometer is presented. The moire interferograms of the plume were processed with computer digital image process technique. It was found that the grey distribution of the moire interferograms has a sharp valley, and from the analysis this paper presented a method to thin and trace a deformated moire fringe on one step. This paper presented the result of the quantitative measurement.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, the experimental results are presented which is by using a small pulsed YAG laser to ignite detonatingpowder to produce temperature field of transient combustion and by using a method of serial pulsed laser interferometry toobtain time series interferograms of combustion process of detonating powder. By means of computer, a detecting methodof fringes thinning is used to thin the fringes of time series interferograms, and fringes displacements are read automatically,and the transient temperature distribution of combustion field of detonating powder and the changes of temperature withtime in the combustion process are calculated quantitatively. 1. INTRODUCTION In general because of instantaneity, destructiveness and danger of detonating powder explosion, only high speed shadowgraphy' and high speed camera2 were used to observe the phenomenon of explosive field and combustion processof detonating power quanlitatively. It is very important for research worker by using no—contact interferometry to measuretransient combustion temperature of detonating powder.In this paper, a small type pulsed YAG laser is used to ignite detonating powder to produce transient combustion fieldand a method of serial pulsed laser interferometry is used to visualize the time series interferograms of temperature field incombustion process. The serial pulsed laser interferometry consists of a large—aperture and long—path interferometer, timeserial pulsed He—Ne laser source and high speed scanning camera. With this method, the time series interferograms of mi-tial combustion process of detonating powder are obtained. From these interferograms, the transient temperature distribu-tion of detonating powder combustion field and the changes of temperature with time in the combustion process are calcu-lated quantitatively with the computer imge processing techniques.

The design principles of a large-aperture high-sensitivity and high-precision moire deflector in which two error-correction methods of real-time holography are used to make grating are presented. Theories and experiments show that this moire deflector has high sensitivity and high precision in measurement, and its system errors are eliminated.

The optical layout, the application, and the working principle of a large-aperture long-range moire interferometer (MI) for the quantitative measurement of flow properties are introduced. The interferometer is easily converted from a schlieren, and is easily tuned by practitioners of experimental flow mechanics.

In this paper, a new method of 3-D object recognition using optical techniques and a computer is presented. We perform 3-D object recognition using moire contour to obtain the object's 3- D coordinates, projecting drawings of the object in three coordinate planes to describe it and using a method of inquiring library of judgement to match objects. The recognition of a simple geometrical entity is simulated by computer and studied experimentally. The recognition of an object which is composed of a few simple geometrical entities is discussed.

A simple spatial filtering is added in moire deflectometry (MD) which raises the sensitivity, improves the contrast of moire patterns, and makes the viewing plate conjugate to the phase objects under test. This modified system is called moire interferometer (MI). Using the Fourier method, this paper analyzes the measurement principle of MI and obtains a strict relationship between a tested wave function and the shift of moire fringes.

This paper puts forward a new large-aperture high-accuracy interferometer for flow visualization and optical shop testing. The interferometer uses a Twyman-Green interferometer as a beam splitter, and a grating as a detector. Using this interferometer to measure the flow fields in a shock tunnel and to test optical elements obtained some satisfactory results.

In this paper, the equations and the contrast of moire fringes, the sensitivity, and the maximum distance allowed between the two gratings in moire deflectometry (MD) are studied in detail on the basis of wave optics. In the analysis the affection of the transfer function for the propagation of a wavefield and the object-image conjugation are considered.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Self-imaging phenomena still exist when a plane grating is illuminated by a monochromatic arbitrary wavefield. The surfaces of the self images are curved, the curvature is determined by the second partial derivatives of wavefront functions. The larger the distance between the grating and a self image the more curved the surface is. The fringe density in self images is affected by the first partial derivatives of wavefront functions. Wavefront functions must satisfy some conditions so that self-images appear.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A new method of 3-D shape measurement by moire technique is presented. An interferometer and computer were used instead of gratings to obtain moire contour. The principle of it is theoretically analyzed in detail. In order to obtain moire contour without unwanted patterns, we propose a method of obtaining moire contour by XOR logic using a computer. Experimental results are given.

By using optical interference and shadowing methods and an optical path delay set-up, the initial process of laser-induced self-focusing in H2 is studied on one Q-switched YAG laser and a series of time-resolved Mach-Zehnder interferograms and shadows are obtained. Some phenomena during the self-focusing are observed and explained. The theoretical model of moving foci is demonstrated by the experiments discussed in this paper.