基于云模型和证据推理的生态环境安全评价

文章提出了一种生态环境安全综合评价模型。首先构建生态环境安全评价指标体系并划分等级区间, 通过云模型将各指标实际值转化为生态环境安全等级的关联度; 其次结合证据推理与熵权法动静态组合确定指标权重; 然后利用证据推理计算出各指标基本可信度分配函数, 再采用证据融合算法合成出生态环境安全综合评估概率分布; 最后根据“最大关联度准则”得出评价结果。以湖南省为例开展实例研究, 研究结果与模糊综合评价法评估等级结果一致, 验证了所提出方法具有合理性、可行性和有效性。     

质子照射小鼠组织病理损伤的初步观察

利用HI-13串列加速器提供的19 MeV 质子照射麻醉小鼠2, 4, 8和16 Gy ， 照射后不同时间麻醉处死小鼠进行病理组织学观察。 结果显示， 照射后各组小鼠腰背部开始环状脱毛， 病理改变为表皮细胞坏死、 脱落， 皮下水肿， 心、 肝出现小灶性坏死或伴出血， 肝细胞明显再生， 肺组织可出现充血及肺泡间隔明显增厚， 肾小球出现明显固缩、 坏死及消失。 这些病理改变在大剂量照射组尤为明显。 通过观察质子照射小鼠组织病理损伤效应， 为质子损伤的防治研究提供参考依据。Space radiation come from galactic cosmic rays and solar particle events which contain considerable protons is an invisible killer to astronauts. Furthermore， many wounded persons were injured by proton and other heavy ion radiation in a nuclear warhead or nuclear terrorism attack. However， the damage effect of proton radiation is known little in our country. In this study， the proton induced histopathologic changes of mice were observed primarily. naesthetic mice were irradiated with the 19 MeV protons dili vered by HI 13 tandem accelerator at CIAE in different doses(2， 4， 8， 16 Gy). In order to observe the da mage effect， mice were killed by anaesthetic at different time point after radiation， and the tissue sections were analyzed by a histopathologic method. The results show that all of the mice’s backs began displaying ringed depilation at post irradiation day 7. Many epidermal cells necrosis and exfoliation happened， and subcutaneous dropsy was observed. There were some focal necrosis or even followed with bleeding in heart and liver. Hepatocyte evidently regenerated. A hyperaemia was seen in lung tissue and alveolar septum was obviously thickening. Acinus renis represented notable pyknosis， necrosis and disappearance. Especially， these pathologic alteration clearly displayed in high dose groups. In conclusion， proton radiation can induce different grade injury to skin， heart， liver， lung， kidney and other organs. Further studies should be made to deeply understand the mechanism about the proton radiation damage.     

基于遗传算法参数整定的方位保持仪温控系统

遗传算法是一种高效的模拟生物进化过程的全局随机化搜索优化方法，它可直接得到所求解问题的全局最优解。针对方位保持仪，提出了一种分段参数设置与级间控制相结合的三级温控方案，并基于遗传算法对PID控制参数进行了优化整定。同时介绍了整个温控系统的软件实现。大量试验证明该控制策略接近最优，达到了战技指标要求。