A mixed scheme based on Wavelet Transformation (WT) is proposed for image edge detection. The scheme combines the wavelet transform and traditional Sobel and LoG (Laplacian of Gaussian) operator edge-detection algorit...A mixed scheme based on Wavelet Transformation (WT) is proposed for image edge detection. The scheme combines the wavelet transform and traditional Sobel and LoG (Laplacian of Gaussian) operator edge-detection algorithms. The precise theory analysis is given to show that the wavelet transformation has an advantage for signal processing. Simulation results show that the new scheme is better than only using the Sobel or LoG methods. Complexity analysis is also given and the conclusion is acceptable, therefore the proposed scheme is effective for edge detection.展开更多
In order to get a clear understanding of the mechanism of space radiation breeding, a detecting system was manufactured. The system consisted of 3 boards of rice seeds (1# and 2# for Qinghua non-glutinous rice and 3# ...In order to get a clear understanding of the mechanism of space radiation breeding, a detecting system was manufactured. The system consisted of 3 boards of rice seeds (1# and 2# for Qinghua non-glutinous rice and 3# for Pearl early rice, Huiyang) and 10 layers of solid state nuclear track detectors (CR-39) in sandwich (Fig.1). It was loaded in space shuttle Shenzhou 3 (at astronaut seat) in the last 10-day period of March, 2002.展开更多
75 MeV/u oxygen ion (^16O+8) beams supplied by HIRFL were used to irradiate 14615 of spring wheat dry seeds of stable multi-generation. Range of the ions in the seeds is about 11 mm. They can enter the seed from its e...75 MeV/u oxygen ion (^16O+8) beams supplied by HIRFL were used to irradiate 14615 of spring wheat dry seeds of stable multi-generation. Range of the ions in the seeds is about 11 mm. They can enter the seed from its embryo, come out from its top, and penetrate through an entire grain of wheat, length of which is about 6～7 mm. The seeds were vertically inserted in a sample plate of 4 cm in diameter, which can contain about 100 grain of the seeds. During irradiation, the embryo of the seeds faced to ion beams and was irradiated at normal temperature and atmosphere. Irradiation dose was arranged in 1×10^7, 5×10^7, 1×10^8, 2×10^8 and 5×10^8 ions/cm^2 with dose rate of about 3 Gy/min. A part of the irradiated seeds was employed for cytology examination in laboratory, the others were used for breeding in the fields.展开更多
Herbage seeds of legume and grass (Defu, American fine stem spread alkaline grass and so on) were penetrated with 80 MeV/u 20Ne10+ ions supplied by HIRFL, NLHIAL. Average LET in plateau of Bragg curve of the ions was ...Herbage seeds of legume and grass (Defu, American fine stem spread alkaline grass and so on) were penetrated with 80 MeV/u 20Ne10+ ions supplied by HIRFL, NLHIAL. Average LET in plateau of Bragg curve of the ions was 120 keV/μm. Irradiation dose was 40, 60, 80, 100, 150 Gy for leguminous herbage and 15, 20, 30, 40, 50 Gy for grass herbage. Dose rate of irradiation was 3 Gy/min. Irradiation was carried out in atmosphere. Some of irradiated seeds were sown in the fields and others were used to do experiments for cytology.展开更多
The distinguishing feature and current technique progress of tumor treatment with heavy-ion beams is introduced in the paper. Additional superiority to tumor treatment from a radioactive ion beam (RIB) is emphatically...The distinguishing feature and current technique progress of tumor treatment with heavy-ion beams is introduced in the paper. Additional superiority to tumor treatment from a radioactive ion beam (RIB) is emphatically discussed. The experimental research of the radioactive 9C-ion beams aimed at tumor treatment at Heavy Ion Medical Accelerator in Chiba (HIMAC), National Institute of Radiological Sciences (NIRS), Japan is described in detail, La-eluding production of the beams, optimization of parameters, distribution of depth dose, survival effect of cell and comparison of RBE between 9C- and 12C-beams. Results show that under 40 mm thick Beryllium target and 10 mm thick aluminum degrader at full (5%) momentum acceptance, the production rate and purity of the produced 9C-beams are 9.07×10-6 and 82.88% respectively with the primary 12C-beams of 430 MeV/u and 1.8×109 pps. A uniform irradiation field with homogeneity up to 89.6% inside central area 10 mm in diameter is obtained by using spot scanning. In this case, the dose rate at the entrance is 0.5 Gy/h. In survival experiment of cells, the average relative biological effectiveness (RBE) of 9C-beams is 5.28 and 2.93 for 12C-beams in the region around Bragg peak. The RBE of 9C-beams is 1.8 times higher than that of 12C-beams. It indicates that cell-killing efficiency of 9C-beams is stronger than that of 12C-beams. 9C-beams are more efficacious for tumor treatment than 12C-beams.展开更多
基金Supported by the National Defence 973 project(2002HS0604,2002HS0634)
文摘A mixed scheme based on Wavelet Transformation (WT) is proposed for image edge detection. The scheme combines the wavelet transform and traditional Sobel and LoG (Laplacian of Gaussian) operator edge-detection algorithms. The precise theory analysis is given to show that the wavelet transformation has an advantage for signal processing. Simulation results show that the new scheme is better than only using the Sobel or LoG methods. Complexity analysis is also given and the conclusion is acceptable, therefore the proposed scheme is effective for edge detection.
文摘In order to get a clear understanding of the mechanism of space radiation breeding, a detecting system was manufactured. The system consisted of 3 boards of rice seeds (1# and 2# for Qinghua non-glutinous rice and 3# for Pearl early rice, Huiyang) and 10 layers of solid state nuclear track detectors (CR-39) in sandwich (Fig.1). It was loaded in space shuttle Shenzhou 3 (at astronaut seat) in the last 10-day period of March, 2002.
文摘75 MeV/u oxygen ion (^16O+8) beams supplied by HIRFL were used to irradiate 14615 of spring wheat dry seeds of stable multi-generation. Range of the ions in the seeds is about 11 mm. They can enter the seed from its embryo, come out from its top, and penetrate through an entire grain of wheat, length of which is about 6～7 mm. The seeds were vertically inserted in a sample plate of 4 cm in diameter, which can contain about 100 grain of the seeds. During irradiation, the embryo of the seeds faced to ion beams and was irradiated at normal temperature and atmosphere. Irradiation dose was arranged in 1×10^7, 5×10^7, 1×10^8, 2×10^8 and 5×10^8 ions/cm^2 with dose rate of about 3 Gy/min. A part of the irradiated seeds was employed for cytology examination in laboratory, the others were used for breeding in the fields.
文摘Herbage seeds of legume and grass (Defu, American fine stem spread alkaline grass and so on) were penetrated with 80 MeV/u 20Ne10+ ions supplied by HIRFL, NLHIAL. Average LET in plateau of Bragg curve of the ions was 120 keV/μm. Irradiation dose was 40, 60, 80, 100, 150 Gy for leguminous herbage and 15, 20, 30, 40, 50 Gy for grass herbage. Dose rate of irradiation was 3 Gy/min. Irradiation was carried out in atmosphere. Some of irradiated seeds were sown in the fields and others were used to do experiments for cytology.
文摘The distinguishing feature and current technique progress of tumor treatment with heavy-ion beams is introduced in the paper. Additional superiority to tumor treatment from a radioactive ion beam (RIB) is emphatically discussed. The experimental research of the radioactive 9C-ion beams aimed at tumor treatment at Heavy Ion Medical Accelerator in Chiba (HIMAC), National Institute of Radiological Sciences (NIRS), Japan is described in detail, La-eluding production of the beams, optimization of parameters, distribution of depth dose, survival effect of cell and comparison of RBE between 9C- and 12C-beams. Results show that under 40 mm thick Beryllium target and 10 mm thick aluminum degrader at full (5%) momentum acceptance, the production rate and purity of the produced 9C-beams are 9.07×10-6 and 82.88% respectively with the primary 12C-beams of 430 MeV/u and 1.8×109 pps. A uniform irradiation field with homogeneity up to 89.6% inside central area 10 mm in diameter is obtained by using spot scanning. In this case, the dose rate at the entrance is 0.5 Gy/h. In survival experiment of cells, the average relative biological effectiveness (RBE) of 9C-beams is 5.28 and 2.93 for 12C-beams in the region around Bragg peak. The RBE of 9C-beams is 1.8 times higher than that of 12C-beams. It indicates that cell-killing efficiency of 9C-beams is stronger than that of 12C-beams. 9C-beams are more efficacious for tumor treatment than 12C-beams.
