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Camshaft is a key part of marine diesel engines. However, the large residual stresses resulting from the induction hardening to which the cams are submitted may lead to cracks on their contacting surfaces. These cracks have great influence in the service life of the shaft. In order to find the relationship between the induction hardening process parameters and the residual stress field, the process was simulated by the finite element method, and the SYSWELD and ANSYS software were used. The temperature distribution during hardening process and stress field of the camshaft after the process were obtained and analyzed. The thickness of the hardening layer was calculated. The simulation results were validated by residual stress measurement experiments and showed a good agreement with the practice. The method reported on the present paper provides an efficient way to analyze the camshaft induction hardening process and avoid the surface failure of the cams.

Terahertz time-domain spectroscopy (THz-TDS) technology has developed rapidly in the past decades, and it has become an important method in the field of spectral analysis. Traditional THz-TDS can only analyze isotropic materials. But the need to add polarization analysis in THz-TDS is becoming more and more urgent. In this paper, a polarization THz-TDS system is established. The birefringence and polarization dependent loss parameters of YVO4, Iceland spar, MgF2, quartz in the terahertz band had been measured. Among them, the birefringence parameter of quartz, MgF2 and Iceland spar at 0.9 THz is in good agreement with the literature. The minimum polarization dependent loss of the four crystals between 0.2THz and 1.5THz are 3.03dB, 4.42dB, 4.4dB and 2.94dB, respectively.

Responsivity is one of the important technical parameters of the detector. With the development of ultraviolet detector technology, ultraviolet focal plane array devices have also been rapidly developed. Therefore, it is increasingly important to accurately measure the response of ultraviolet detectors. This paper analyzes the principle of UV focal plane array response measurement, uses the alternative method to measure the response of the UV focal plane array detection device, and establishes the UV focal plane array response measurement device. The results of uncertainty analysis show that the uncertainty of the UV focal plane array device response measurement system is about 4.2 %, can meet the measurement requirements.

As an important transmission component of diesel engines, the connecting rod has to meet a very high processing accuracy. However, as an elongated part, the connecting rod has a weak rigidity, and the unevenness of the cutting force and the clamping force during the machining processes will lead to the deformation of the connecting rod. In previous researches, cutting and clamping are always studied separately, and their interactions are neglected. In this paper, the finite element simulation method is used to analyze the deformation of the connecting rod. Based on the Deform-3D software, the article builds a connecting rod milling finite element simulation model and predicts the residual stress of the connecting rod milling simulation and the formation of milling chips. The residual stress of the simulation is compared with the residual stress of the experimental measurement and the simulation chip is compared with the actual chip to verify the accuracy of the simulation model, which provides a theoretical basis for the model construction of the next simulation study. Based on the Deform-3D software, simulation studies the influence of different milling parameters on the deformation of the connecting rods. And optimize the link milling process parameters. Based on ANSYS software, the effect of superposition of cutting force and clamping force on machining deformation of the connecting rod was simulated and analyzed. The resultant milling force should not be greater than 734N. This method makes up for the defects that cutting and clamping are studied separately and their interactions are neglected.

Searching for and adjusting to the appropriate wheel positions for designed grooves are among the key issues in the manufacturing of the end mill, drill and other integral cutting tools. Along with the increasing requirements of product categories and quality, a large number of non-traditional and customized grooves continuously appear. However, as multivariable, nonlinear and multiple target problems, it is difficult to obtain the desired wheel position. Therefore, we introduce an intelligent method to search for the optimum wheel position for the designed groove with the known wheel geometry. According to practice, the basic parameters of the groove and wheel geometries are introduced, and the problems studied in this paper are explained. As a foundation, a robust algorithm is built to predict machined grooves with a series of equal distribution points and three parameters: the rake angle, core radius and groove width. The influence that the wheel positions have on groove geometries is then analyzed. Then, an objective function considering different machining requirements is built, and the optimum wheel positions are searched for while the function is solved. Furthermore, an enhanced niche particle swarm optimization (NPSO) algorithm is developed to solve the problem. Finally, 6 experiments are carried out to verify and analyze the algorithm. The results show that the algorithm can effectively find the desired wheel positions according to different machining precision requirements.

Groove is one of the key structures of end mills. Some of them could be machined by standard grinding wheels (1A1 or 1V1 type), some others must design new wheel profiles. Based on the enveloping and analytic geometry theories, a novel algorithm was proposed to calculate the wheel profiles for special groove machining. The machining process was analyzed, the contact line principles were discussed, and the calculation procedure was detailed. In addition, the algorithm was implemented on a personal computer by using the MATLAB programming language. Therefore, the desired wheel profile could be computed automatically with four input parameters, namely, the groove lead, the wheel axial vector, the point coordinates on the wheel axis, and the discrete points on the groove profile (or groove profile expression). The proposed algorithm and the corresponding program were finally verified by three different examples. The results demonstrated good agreements with the practical wheel profiles.

Helical groove geometry has important influence on the performance of end mills. It is the hardest and most time-consuming grinding process in end mill manufacture. This paper reports a graphical analysis method to obtain the structure parameters and geometric shapes of helical grooves with the known wheel geometry and position. Mathematical models are presented to describe the wheel geometry and position (including orientation and location) in space. A family of wheel surfaces is calculated and a scattered point set in the cross section plane is deduced according to the grinding path. Finally, an original algorithm for the cross sectional outline profile identification is given using graphical method. To verify this method, a calculation program programmed using MATLAB programming is developed. This study provides a fundamental understanding for the groove grinding process, based on this, the influence of different grinding process parameters on groove geometry (including radial rake angle, groove width and core radius) is discussed.

Helical groove is one of the key structures of end mills. Its grinding process is the hardest and most time-consuming in end mill machining. According to the practical groove-grinding process, a Boolean method to simulate the groove-grinding process is proposed in this paper. The groove model is obtained with the known wheel geometry by a sequence of Boolean operations. Accordingly, the wheel used to machine a desired groove is deduced with the similar method. Based on the Boolean operation results and principles of differential geometry, contact lines of the wheel and groove are illustrated and calculated to optimize the groove-grinding process. Wheel positions relative to the blank are described by a sequence of mathematical coordinates. Wheel profile expressions are built with the corresponding transformation matrixes including groove geometry transformation matrix, cutter tip transformation matrix, and start processing position transformation matrix. Some simulated examples are included to illustrate the presented method.

Clearance of end mills has great impact on the performance of milling, and therefore a high demand for its machining theory and process is put forward. Based on the analysis of practical machining process, enveloping theory, principles of spatial geometry are introduced to establish the clearances processing model, as well as considering the geometries, orientations, and locations of wheels used to machine the clearances with convex, eccentric, or elliptic shapes. Accordingly, limitations of wheel geometry and location to machine a desired clearance are discussed. A commercial computer aided design system with API function programming is used to visualize the machining process. The solid model is finally obtained.

A purely analytical method, based on the meshing theory, is presented to establish the exact helical groove and circumferential cutting edge model of end mills, for the solution of its low design precision and efficiency problems. Firstly, a coordinate system to represent the relative space position relations between grinding wheels and end mills is built and the mathematical model of the helical groove is precisely calculated with a given wheel profile and relative movements between the wheel and the workpiece. Then, the rake angle, inner radius and wheel positions of machining the clearance faces is computed. Finally, a 3D model of the end mill is generated by using OpenGL.

The aims of this study were to investigate intrapapillary capillary loops (IPCLs) of superficial esophageal lesions changes in different types classified by the Japan Esophageal Society classification. The calibers, areas, and densities of IPCLs were detected in 34 cases of esophageal lesions using immunohistochemical analysis. Statistically significant differences in calibers, areas, and densities of IPCLs were observed between type A, type B1/B2, and type B3 area (P

This paper describes a new approach to establish the helix flute model of solid carbide end mills. Based on the theory of differential geometry and coordinate transformation, a mathematical model of the end mill helix flute will be established.The main idea of the study is to envelop the helix flute by a one-parameter surface group which consists of the cross-sectional profiles of the wheel.Then, the mathematical model will be quickly verified by MATLAB.Thus the end mill design time will be saved and the new mathematical model will be checked effectively.

1.5 MW Ion Cyclotron Wave Heating system was developed, the transmitter and the antenna both have their ground loops, which will severely perturb the system's normal operation. To avoid perturbation, a DC break was designed. The S parameter and the VSWR (voltage standing wave ratio) of incident port were calculated; the thermal effect caused by conductor loss and dielectric loss was analyzed.

By analyzing common artificial intelligence technologies, the paper introduced design of software and structure of a drainage system of coal mine underground based on artificial intelligence control. By detecting water level in sump and other parameters, the system controls pumps to work by turns and standby pump to start at duly time, so as to schedule dumps run reasonably, and it has function of fault alarming, which decreases labor intensity of workers greatly and improves utilization rate of devices. The system also has good expansibility and is fit for different fields.

Taking into account the turn off time of the Q-switch, the coupled equations for a mid-infrared KTiOAsO4 optical parametric oscillator (OPO) are given. These rate equations are solved numerically and some key parameters for designing the laser system are determined. The key parameters include the optimal coupling and nonlinear crystal length which maximize the output power and OPO conversion efficiency. We found that a low-loss singly resonant OPO cavity not only enhances the mid-infrared output but also decreases the optimal OPO crystal length.