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For a quantitative understanding of light interaction with fruit tissue, it is critical to obtain two fundamental parameters: the absorption coefficient and the scattering coefficient of the tissue. This study was to investigate the optical properties of kiwifruit tissue at the wavelength of 632.8 nm. The total reflectance and total transmittance of kiwifruit tissue from three parts (including the flesh part, the seed part, and the seed-base part) were measured using a single integrating sphere system. Based on the measured spectral signals, the absorption coefficient μ a and the reduced scattering coefficient μ s' of kiwifruit tissue were calculated using the inverse adding-doubling (IAD) method. Phantoms made from Intralipid 20% and India ink as well as a Biomimic solid phantom were used for system validation. The mean values of μ a and μ s' of different parts of the kiwifruit were 0.031–0.308 mm−1 and 0.120–0.946 mm−1, respectively. The results showed significant differences among the μ a and μ s' of the three parts of the kiwifruit. The results of this study confirmed the importance of studying the optical properties for a quantitative understanding of light interaction with fruit tissue. Further investigation of fruit optical properties will be extended to a broader spectral region and different kinds of fruits.

A numerical simulation mathematical model and sloved method about injection forming for thin-wall part was established. Based on it, Simulation of the injection forming process of centrifugal separation disc. Through the simulation of forming process for PA66 and PA66+30%GF two kinds of materials, realized the injection forming for centrifugal separation disc using PA66+30%GF. Through the anisotropy of glass fiber orientation, improve the stiffness and toughness for centrifugal disc.

With globoidal indexing cam mechanism as the object of study, this paper introduces its operating principle, analyzes and calculates its main motion parameters. On the basis of theoretical study, the paper using structured program design method and Visual Basic 6.0 as developing tool analyzes main function modules, such as system parameters input, law of motion, kinematics analysis and pressure angle check, etc. The paper develops globoidal indexing cam mechanism CAD system in simple operation and describes application method of the system and design examples.

The performance of twin-screw compressor is mainly decided by profiles of the two rotors. The constitution of new rotor profiles is studied, meanwhile the key technology of generating rotor profiles are mainly studied in this paper. A new method based on forward and reverse direction for generating rotor profiles with meshing lines is proposed.

In this paper, a novel surface reconstruction method is presented to creat a composite surface with point data on surface obtained by CMM. In this method, the 3th non-uniform B-spline algorithm is proposed to reconstruct every single free-form surface on the whole composite surface, and the algorithm for surface blending is proposed to merge every single surface together to achieve the level of G1 continuity. Furthermore, in order to check and visualize the reconstruction model, a special closed-loop RE system is developd by VC++ to constantly guide to measure and reconstruct untill the model fits in with requirements. Examples are included to illustrate the approach.

In the traditional screw compressor rotors profile generation method, the process of cockamamie parameters adjustment and confirmatory will take a long time, so that the modified results can’t be estimated in advance. Based on freeform curve, two rotor profiles generation methods are presented in this paper. One method is positive, and the female and male rotor profiles are acquired by every profile segment defined with freeform curve; another one is reverse, and the rotor profiles are derived through the meshing line. The rotor profiles are fitted by freeform curve and the shape of rotor profile can be adjusted by moving the control points. Finally, the two methods are used to developed a system for designing quickly the rotor profiles.

In this paper, it is proposed a new method of free-from surface’s reverse engineering, making data acquisition and surface reconstruction form closed loop system, solving no feedback problems in the measuring and modeling process, shortening the time of the whole reverse engineering, improving the quality of reconstructed models. The core of this paper is used the CMM adaptive measuring method and non-uniform b-spline surface reconstruction method, integrating the free-from surface measuring and modeling in a closed loop system, realizing the CMM real-time online measurement and reconstructed surface real-time update.

Take spare parts from front cylinder head of compressor as an example, the essay analyze feature of parameter in snap ring grooves, measure dimension error of cone angle in snap ring grooves in method of comparative measurement, solve the problem that parameter of similar spare parts can not be measured, implement gauge detection of size of snap ring grooves in method of comparative measurement.

Surface reconstruction by alpha geometric shape based on triangulation is a new idea and method in computer graphics and reverse engineering. In the process of Topology reconstruction, the points are reduced and projected to a middle slice plane. The adjacency among slices is established by section line subdivision, and triangle mesh is stored and called by the form of STL. The simplexes are classified and computed in order to obtain α interval by the external-ball radius and center of every simplex, and the data structure is designed to save them. Through the man-machine interactive selection modes, α-shape can be reconstructed by different α parameters. The surface reconstruction is completed.

Convex hull is a very important data structure of computational geometry design. This paper presents an algorithm to construct the convex hull of a set of scattered points by coordinates and relative angle method. The algorithm determines the convex vertexes and eliminates some non-convex vertexes, which greatly reduces the searching scope and the complexity. Delaunay triangulation is widely used in 3D surface reconstruction. Due to its duality, Delaunay triangulation is usually constructed through Voronoi diagram. Delaunay triangulation is directly constructed in this paper. The algorithm is simple, stable and easy to implement, especially for less data points.

To seek better methods of measurement and more accurate model of reconstruction in the field of reverse engineering has been the focus of researchers. Based on this, a new method of adaptive measurement, real-time reconstruction, and online evaluation of free-form surface was presented in this paper. The coordinates and vectors of the prediction points are calculated according to a Bézier curve which is fitted by measured points. Final measured point cloud distribution is in agreement with the geometric characteristics of the free-form surfaces. Fitting the point cloud to a surface model by the nonuniform B-spline method, extracting some check points from the surface models based on grids and a feature on the surface, review the location of these check points on the surface with CMM and evaluate the model, and then update the surface model to meet the accuracy. Integrated measurement, reconstruction, and evaluation, with the closed-loop reverse process, established an accurate model. The results of example show that the measuring points are distributed over the surface according to curvature, and the reconstruction model can be completely expressed with micron level. Meanwhile, measurement, reconstruction and evaluation are integrated in forms of closed-loop reverse system.

To observe the dynamic changes of alveolar apoptosis in ischemia-reperfusion (IR) induced pulmonary injury, and to evaluate the roles of these two cell death styles, apoptosis and necrosis, in the progress of lung function deterioration in pulmonary IR injury.Fifty-four Sprague-Dawley rats were made ischemia/reperfusion models by ischemia and reperfusion in situ in single lung. Thirty-six of the 54 rats in the experimental group were re-divided into 6 equal subgroups to undergo detection of partial pressure of oxygen (PaO2) of blood in left atrium, detection of lung tissue wet weight/dry weight ratio, histology of lung by light microscope, examination of ultrastructural changes of cells by transmission electron microscopy, and quantitative detection of apoptotic cells in the right middle lobe by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) 0 h, 0.5 h, 1 h, 2 h, 6 h, and 12 h respectively after the reperfusion (subgroups R0, R(0.5), R1, R2, R6, and R12). Another 18 rats in the experimental group were re-divided into 3 subgroups of 6 rats to undergo insertion of venous catheter into the main pulmonary artery via right ventricle to perfuse trypan blue so as to evaluate the cell death degree. The death index was observed under light microscope and the necrosis index was indirectly calculated by the equation: death index = apoptotic index + necrosis index. Thirty-six rats underwent sham operation. Twelve rats were used as preoperative blank controls.Proliferation of alveolar type II, but not alveolar type I cell, accompanied by ultrastructural morphological changes were seen 1 h, 2 h, and 6 h after reperfusion, the most prominently 2 h after reperfusion. Apoptotic index was elevated since 1 h after reperfusion, and peaked 2 h after reperfusion. Statistical analysis indicated that, compared with apoptotic index, the necrotic index was of more prominent correlation with blood oxygen partial pressure and wet/dry weight ratio.Alveolar apoptosis occurs in the early stage of reperfusion, and becomes the most prominent 2 h after reperfusion. Most apoptotic cells are alveolar type II cells. In the two styles of cell death in pulmonary IR injury, alveolar necrosis is more prominently correlated with progress of lung function deterioration.