彩色AC-PDP运动图像仿真系统的开发

开发了彩色AC-PDP运动图像仿真系统,通过利用本系统的运动图像仿真功能可以对现有的各种显示技术、与子场有关的各种因素进行仿真及比较,为人们开发提高彩色AC-PDP图像显示质量的新型技术及子场提供了理论上的依据;通过利用本系统的Gamma特性研究功能可以对彩色AC-PDP中视频信号的反Gamma特性进行研究,并对反Gamma相关编码进行子场逼近,为选择符合要求的子场编码提供了判据.     

灭菌处理对纳米羟基磷灰石增强聚酰胺66 复合材料性能的影响

不同灭菌方法都有可能对骨修复生物材料的物理和化学性能产生影响。骨修复生物材料的力学性能决定了整形外科手术的短期或中长期结果。文中采用IR,XRD和常规力学性能测试等方法研究了蒸汽灭菌和γ射线辐照灭菌对纳米羟基磷灰石增强聚酰胺66(n-HA/PA66)骨修复复合材料的物理化学性能的影响。XRD和IR分析结果表明,两种灭菌方法都不会改变n-HA/PA66骨修复材料中两相的功能团结构和晶体结构。蒸汽灭菌过程会降低材料的拉伸强度,杨氏模量,压缩强度和弯曲强度;而γ射线辐照灭菌处理对材料的力学强度有一定增强作用。     

Fluorinated Polyphosphazenes: A Survey

A general survey of fluorinated phosphazene polymers starting from their synthesis in 1965 to recent times is presented. Various types of fluorinated phosphazenes are described depending on the way fluorine atoms are connected to the polyphosphazene skeleton. The characterization, properties and practical utilization of these compounds in different domains are critically discussed.     

Measurement of 76Se and 78Se (γ, n) Cross Sections

The (γ, n) cross sections of Se isotopes (⁷⁶Se,⁷⁸Se) were measured to supply fundamental data for estimating the inverse reaction cross section, i.e., the ⁷⁹Se(n, γ)⁸⁰Se cross section. The enriched samples and a reference ¹⁹⁷Au sample were irradiated with laser-Compton scattering (LCS) γ-rays. The excitation function of each (γ, n) cross section was determined for the energy range from each near neutron separation energy to the threshold energy of (γ, 2n) reaction. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS γ-rays. Systematic (γ, n) cross sections for Se isotopes including ⁸⁰Se were compared with those calculated by using a statistical model calculation code TALYS.     

Measurements of Photon Mass Attenuation Coefficients for Ge and BGO Crystals at 10 Me V

The photon mass attenuation coefficients of the important materials for γ-ray detection, Ge and BGO (Bi₄Ge₃O₁₂) crystals, have been measured for 10.0 MeV γ-rays. The measurement system using the laser-Compton backscattering γ-rays and the high-resolution high-energy photon spectrometer has been developed and utilized. The effectiveness of the system achieving the total systematic uncertainties of 0.5% for the measurements of the photon mass attenuation coefficients was demonstrated. It was shown that the measured photon mass attenuation coefficients, 318.1 ± 1.7 [cm²/g] for the Ge crystal and 425.2 ± 2.4 [cm²/g] for the BGO crystal, agree within the achieved experimental uncertainties with the evaluated values including atomic and nuclear processes at 10.0 MeV.     

The Extraction of Curium and Americium by Tri-n-Octyl Phosphine Oxide

Magnesium chromate anhydrate, magnesium chromate monohydrate and sodium chromate quadrahydrate were irradiated in the Liquid Nitrogen Temperature Loop at the Japan Atomic Energy Research Institute to study the behavior of ⁵¹Cr recoil atoms. The initial retentions of recoil ⁵¹Cr were measured at ?55°, ?40° and ?30°C, and the thermal annealing behavior of recoil ⁵¹Cr was examined extensively in the temperature range from ?20° to 80 °C. The effects of difference in total irradiation dose and of the water of crystallization on the annealing behaviors of ⁵¹Cr recoil atoms are discussed.     

Peroxidation of Polymethylhydrogensiloxane and Cellulose by γ-Irradiation in Air and Grafting Induced by Their Decomposition

The peroxides of polymethylhydrogensiloxane, cellulose and a mixture of both were determined by ferrous ion method. The relation between the decomposition of the peroxide and the degree of grafting by standing at an elevated temperature after irradiation was examined.

The G-value for the peroxide formation of polymethylhydrogensiloxane was found to be 8.7, and the activation energy for the peroxide decomposition was determined from calculation to be 43 kcal/mol. The ratio of G-values of silicone between those terminated by methyl radical and by methyl radical is estimated to be about 2/1. It would thus appear certain that the rate of peroxidation is affected by the end group. The peroxidation is not a chain reaction at room temperature, and the peroxide is produced by the recombination of the peroxy radical. At least two types of peroxide are produced by irradiation in air, and one is decomposed at 80°C but the other is relatively stable.

On the other hand, the G-value for the peroxide formation of cellulose is equal to 5.6.

The tendency seen for the decrease of the peroxide corresponds to that of increasing degree of grafting, and it may be concluded that only 1/10 of the peroxides formed in the cellulose–silicone system results in grafting, since it has been calculated that the G-value for the grafting through the peroxide is about 1.0.     

Chain Dechlorination of Organic Chlorinated Compounds in Alcohol Solutions by 60Co γ-Rays, (III)

Chlorinated benzenes dissolved in deoxygenated alkaline 2-propanol were dechlorinated by irradiating with ⁶⁰Co γ-rays to produce the lower chlorinated benzenes and chloride ion. The yield of dechlorination was found to depend on the number of chlorine atoms on the benzene ring, the G (CI^?)-values being, for instance, 6,500, 480 and 2.0 for 0.07 M penta-chlorobenzene, 1, 2, 4-trichlorobenzene, and monochlorobenzene, respectively, in 0.2 M KOH-2-propanol solution. In contrast, the values of G(C1^?) differed little between the isomers of trichlorobenzene. The large difference in G (CI^?) according to the number of chlorine atoms can be explained by considering the redox potential of the chlorinated benzenes and the ketyl radical ion.

Trichlorobenzene is dechlorinated to dichlorobenzene and then to monochlorobenzene while producing potassium chloride and acetone, and consuming hydroxide ion. In the experiment, some chlorinated benzene derivatives were observed to be generated in the course of this process—probably dichlorophenyl-2-propanol and monochlorophenyl-2-propanol, judging from observation by gaschromatograph-mass spectrometer and from the path-way of formation. The observation also indicated the presence of dichlorophenyl-2-propanol in predominant amounts in 1, 3, 5-trichlorobenzene solution, but only in a small fraction in 1, 2, 3-trichlorobenzene.     

Half-Lives and Gamma-Ray Energies of Short-Lived Molybdenum Isotopes

Short-lived molybdenum isotopes produced by the ²³⁶U(n, f) reaction were isolated by rapid paper electrophoretic technique. Gamma-ray spectra of the isolated molybdenum fraction were measured with high resolution Ge(Li) detector. The half-lives of ¹⁰³Mo (70±1 sec), ¹⁰⁴Mo (66±2 sec) and ¹⁰⁵Mo (30±3 and 40±5 sec) were determined by analyzing the genetic relationships of the known photopeaks of their technetium daughters. Decay analysis of observed photopeaks free from interference resulted in the detection of many new short-lived photopeaks with half-lives of 10–70 sec, and which were not relevant to technetium isotopes. These new photopeaks were ascribed to ^103-106Mo, based on examination of their decay behavior.