在极低温下照射种子的生物学效应 Ⅲ·液氮低温的刺激增产和诱变作用

基于极低温对种子γ辐射效应的影响,研究了液氮低温(-196℃)单因子的生物学效.发现液氮处理冬小麦风干种子,不仅有损伤效应,也有刺激增产和诱变作用.实验结果表明:在液氮中进行种子γ照射应考虑这些因素,并对发展中的低温生物学也提出了有待研究的新问题.     

飞行器射频隐身技术研究综述

随着现代电子对抗技术和军事装备的不断发展,无源探测系统对飞行器及其所搭载有源电子设备的探测能力得到了显著提高,飞行器在现代作战环境中的生存能力和突防能力受到了严重威胁.飞行器射频隐身技术是通过控制机载雷达、数据链、高度表、电子对抗等机载有源电子设备射频辐射以提高飞行器战场生存能力的重要技术途径,在当今战场中起着重要作用...     

Radiation embryology

Summary Prenatal development, characterized by intensive cell proliferation, cell differentiation and cell migration, shows a high radiosensitivity. Therefore, radiation exposure of embryos and fetuses is of great concern for radiological protection and human health. Irradiation during gestation can cause death, growth disorders, malformations, functional impairment and malignant diseases in childhood. These effects are strongly dependent on the developmental stage at exposure and on the radiation dose. The first trimester of pregnancy is regarded as the period with the highest risk for malformation and cancer induction. The developing nervous system shows a special susceptibility to ionizing radiation over a long period and is therefore of great significance for risk estimation. Knowledge about radiation effects on prenatal development has been derived from animal experimentation and from the exposure of human embryos. There is evidence that doses between 1 and 10 cGy may lead to developmental anomalies and that the radiation response can be modified by additional factors.     

新型辐射物体杂质检测法

当物体复合成份中某一种成份存在较多时，用频闪观测方法测量物体复合成份发光辐射时间参量。本文给出了测量的基本原理和算法，给出了此方法装置图。此方法与其他方法相比具有较高的时间测量灵敏度。物体发光辐射的这种测量方法可在犯罪侦查学、司法医学鉴定及相应的海关、税务部门使用。     

在极低温下照射种子的生物学效应——Ⅳ.对辐射细胞学效应的观察

以微核测定法,对极低温(-196℃)和常温下照射材料的细胞学研究结果表明:极低温有保护效应,能减轻M_1代的生理损伤:辐射种子萌动芽尖间期细胞的微核率与M_2代某些性状突变率具有一定的相关性;极低温单因子处理种子亦可导致染色体畸变。该实验为阐明极低温对种子照射效应的影响提供了微观依据。     

蜚蠊壳聚糖的快速制备方法研究

研究微波方法快速制备蜚蠊壳聚糖的实验条件，运用L9(3^4)正交实验法，将碱浓度、时间、微波加热温度、料液比在三个不同水平上进行优选实验，得出最佳制备条件为45％的NaOH，温度100℃，时间30min，壳聚糖脱乙酰度可达84．9％．此工艺比常规方法时间短，得率较高．     

一个新的黑体辐射γT关系式及其应用

用Gauss—Lagurre近似方法推导出使热辐射效率最佳化的一个新的黑体辐射λT关系式,讨论了该关系式及其适用范围,并给出了应用举例.     

Serum thymic factor as a radioprotective agent promoting survival after X-irradiation

Summary Serum thymic factor (FTS, zinc-free thymulin) protected mice from death after whole-body X-irradiation. It was significantly radioprotective even when administered after irradiation, but it was more effective when administered both before and after irradiation. The protective effect appears to be due to the enhancement of hematologic recovery in the animals.     

The consequences of the discovery by W. C. Röntgen for present-day medical physics and radiation protection

When the German physicist W. C. Röntgen discovered X-rays, which were named after him, he introduced a new development in medicine and biology: together with the discoveries of A. H. Becquerel and M. Curie, radiology with its diagnostic and therapeutic methods was made possible. The medical physicist has an important task to fulfill in modern radiotherapy, nuclear medicine and radiodiagnostics. The longtime interdisciplinary collaboration has won the international recognition of medical physics as a scientific discipline, a health care profession and a university subject. Several incidents, including contemporary ones, show that the efforts made towards radiation protection must remain an important domain of the specialist.