摘要:
A method for four-dimensional (4D) image verification in respiratory gated radiation therapy, includes: acquiring 4D computed tomography (CT) images, each of the 4D CT images representing a breathing phase of a patient and tagged with a corresponding time point of a first surrogate signal; acquiring fluoroscopic images of the patient under free breathing, each of the fluoroscopic images tagged with a corresponding time point of a second surrogate signal; generating digitally reconstructed radiographs (DRRs) for each breathing phase represented by the 4D CT images; generating a similarity matrix to assess a degree of resemblance in a region of interest between the DRRs and the fluoroscopic images; computing a compounded similarity matrix by averaging values of the similarity matrix across different time points of the breathing phase during a breathing period of the patient; determining an optimal time point synchronization between the DRRs and the fluoroscopic images by using the compounded similarity matrix; and acquiring a third surrogate signal and turning a treatment beam on or off according to the optimal time point synchronization.
摘要:
A method for four-dimensional (4D) image verification in respiratory gated radiation therapy, includes: acquiring 4D computed tomography (CT) images, each of the 4D CT images representing a breathing phase of a patient and tagged with a corresponding time point of a first surrogate signal; acquiring fluoroscopic images of the patient under free breathing, each of the fluoroscopic images tagged with a corresponding time point of a second surrogate signal; generating digitally reconstructed radiographs (DRRs) for each breathing phase represented by the 4D CT images; generating a similarity matrix to assess a degree of resemblance in a region of interest between the DRRs and the fluoroscopic images; computing a compounded similarity matrix by averaging values of the similarity matrix across different time points of the breathing phase during a breathing period of the patient; determining an optimal time point synchronization between the DRRs and the fluoroscopic images by using the compounded similarity matrix; and acquiring a third surrogate signal and turning a treatment beam on or off according to the optimal time point synchronization.
摘要:
A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.
摘要:
A method for producing pistons that can be used in internal combustion engines made from lightweight metal, with a combustion bowl assigned to one piston head, wherein a bowl rim is subjected to a melt treatment. In a first method step, the bowl rim is inductively heated. In a second method step, the material of the bowl rim, also to be referred to as the delimiting zone, is improved by means of a laser beam.
摘要:
A process for hardening an annular groove of a piston head of a piston of an internal combustion engine by means of laser beams, in which, at least the annular groove to be hardened is provided before or directly during the hardening process with a coating which absorbs the energy of laser beams. The coating is subsequently irradiated by the laser beams. The absorbing layer can be a manganese phosphate coating or is formed in situ by treating the component surface with a process gas comprising oxygen and inert gas. Furthermore, the laser beams are directed at the piston during hardening at an oblique angle to the direction of rotation. The advantages achieved are avoidance of reflections and undesirable hardening of the bottom of the groove, an increased degree of absorption and reduced distortion of the piston.
摘要:
A method for producing a piston of an internal combustion engine, wherein the piston has a combustion bowl including a combustion bowl rim. The combustion bowl rim is hardened by being remelted in a first step by means of an inductive energy supply and, in a further step, by a laser beam. The beam can be deflected during a rotary, progressive motion relative to the piston.
摘要:
The invention relates to a process for hardening an annular groove of a piston head (1) of a steel piston of an internal combustion engine by means of laser beams (4), in which, according to the invention, at least the annular groove to be hardened is provided before or directly during hardening with a coating which absorbs the energy of laser beams (4) and the coating is subsequently irradiated with the laser beams (4). The absorbing layer is preferably a manganese phosphate coating or is formed in situ by treating the component surface with a process gas comprising oxygen and inert gas. Furthermore, the laser beams are directed at the piston during hardening at an oblique angle to the direction of rotation. The advantages achieved are: avoidance of reflections and undesirable hardening of the bottom of the rotation. The advantages achieved are: avoidance of reflection and undesirable hardening of the bottom of the groove, an increased degree of absorption and reduced distortion of the piston.
摘要:
The invention relates to a paper of value (1) with at least one security feature (3), in particular a bank note (1), as well as a method and an apparatus for producing such a paper of value (1). By virtue of e.g. bank notes (1) being produced with at least one rounded corner area (4a-d, 4a′-d′), the likelihood of the formation of dog-ears and thus of jams during automatic tests in bank note processing machines is reduced.
摘要:
The invention relates to a method of stabilizing natural composites against damage by heat and light by treating the wood derived fillers with a water based solution of a sterically hindered amine, drying the treated wood derived filler and then combining with plastic via compounding methods such as extrusion.