退火温度对Fe73.5Cu1Nb3Si13.5B9合金磁后效和正电子寿命的影响

测量了制备态和经不同温度（ｔａ ＝ ４５０ ～７５０ ℃） 退火的Ｆｅ７３－５Ｃｕ１Ｎｂ３Ｓｉ１３－５Ｂ９ 合金的室温磁后效和正电子寿命·发现在６００ ℃以下退火,随着退火温度升高,磁后效和正电子寿命都单调下降;在６５０ ℃以上退火,磁后效基本被抑制,正电子寿命出现两个值,它们分别对应自由体积和空位聚集体,且后者显着增大·实验结果表明,磁后效主要由材料中的非晶相所贡献,这是由于非晶相中存在大量自由体积的缘故·     

巴尔虎人5项舌运动类型的人类学研究

对呼伦贝尔市286例(男95,女191)巴尔虎人的卷舌、叠舌、翻舌、尖舌、三叶舌5项舌运动类型进行了调查研究.结果发现:(1)巴尔虎人卷舌、叠舌、翻舌、尖舌、三叶舌出现率分别为80.42%、6.64%、38.81%、79.72%、16.43%;除叠舌外,巴尔虎人的其他4项舌运动类型在性别间的差异均无统计学意义.(2)在我国各族群中,巴尔虎人卷舌、翻舌出现率偏高,叠舌、尖舌出现率中等,三叶舌出现率偏低.(3)聚类分析结果表明,巴尔虎人与蒙古族其他族群(厄鲁特蒙古族、科尔沁蒙古族、锡林郭勒蒙古族、察哈尔蒙古族、布里亚特蒙古族和乌拉特蒙古族)舌运动类型出现率接近.(4)卷舌与翻舌、尖舌、三叶舌,叠舌与尖舌彼此间存在基因互作关系.巴尔虎人5项舌运动类型具有北亚类型族群的基本特征.     

藏医药学实验教学模式改革探讨

通过实验、实习、实践教学使学生认识、了解和熟悉藏医人体三因(隆、赤巴、培根)和各组织器官的形态、结构、功能以及在疾病状态下的改变,使学生在学习的同时能够进行藏药药效物质基础、传统方剂配伍规律和藏药炮制技术等的初步研究。在充分掌握传统藏医药对人体、疾病、治疗三者辩证统一认识的基础上,了解现代医学实验研究的基本思路、原则和方法,逐步培养了学生的创新思维和初步的科学研究能力。根据藏医药学学科实践性强的特点,把藏医药传统"师带徒"临床实习、野外采认药等实践活动与现代医学室内实验相结合,构建起由"实验+实习+实践"所组成的"三实"结合模式,使学生系统地掌握藏医药实验教学的内容。     

粤北牛岱辉绿岩脉的地球化学特征及其成因研究

牛岱辉绿岩脉位于粤北诸广岩体南部.牛岱辉绿岩具有低SiO2 (45.04％ ～48.64％)、高TiO2( 2.02％～ 3.23％)和TFeO含量(17.00％～ 19.80％)、富集K,Rb,Ba等大离子亲石元素和La,Nd,Eu,Tb等稀土元素、Nb-Ta亏损轻微、稀土总量较高(112.1×10-6 ～132.7...     

物理教育中多媒体技术应用的探讨

本文从多媒体技术的角度讨论其在物理教育中的作用和运用多媒体辅助物理教学所应遵循的原则等问题。     

对珠江流域各区域间旅游经济合作的探讨

旅游经济作为一个可持续发展前景广阔的产业部门，是珠江流域各区域经济合作的重点领域。加强珠江流域各区域问的旅游经济合作既有现实必要性，又有相应的基础条件。加强流域各区域间的旅游经济合作要从树立正确的合作观念、拓展科学的合作方式、建立高效灵活的合作机制、构建灵敏的信息支撑平台、实施差别化管理策略等方面入手，采取行之有效的对策措施，使之沿着健康有效的轨道前进。     

Design of a novel optically stimulated luminescent dosimeter using alkaline earth sulfides doped with SrS:Eu,Sm materials

Optically stimulated luminescence （OSL） is the luminescence emitted from an irradiated insulator or semiconductor during exposure to light. The OSL intensity is a function of the dose of radiation absorbed by the sample and thus can be used as the basis of a radiation dosimetry method. Alkaline earth sulfides doped with rare-earth elements such as Ce, Sm and Eu are OSL dosimeters having very high sensitivity, and the OSL with a short time constant is separated from the stimulated light. In this paper, a novel OSL dosimeter designed with SrS：Eu,Sm materials is described. The dosimeter takes advantage of the characteristics of charge trapping materials SrS：Eu,Sm that exhibit OSL. The measuring range of the dosimeter is from 0.01 to 100Gy. The equipment, which is relatively simple and small in size, is promising for applications in space exploration and high dose radiation dosimetry.     

《外国文学作品选读》双语教学的可行性研究

双语教学有利于帮助二语习得者实现母语正迁移,更好地适应时代发展的需要和自身素质的提高。作为提高高校学生素质的外国文学课程,有其独特的学科特征,有必要把双语教学作为一种独特的教育手段纳入课堂教学领域,使外国文学课堂教学更具特色。通过问卷调查的方式,认为双语教学不仅能激发学生学习兴趣,提高学生语言运用能力,而且有利于提高教师的业务水平。     

交流磁场下7075铝合金液相线和固相线温度变化

在7075铝合金凝固过程中施加频率为50Hz的交流磁场,磁场强度的变化范围为0 06T,0 09T,0 12T·运用双电桥法分别测定了上述凝固过程的电阻 温度曲线,确定了合金在不同磁场条件下凝固的液相线和固相线温度·实验结果表明:在交流磁场中凝固的合金,其液相线和固相线温度均明显提高,并且结晶温度间隔变小,磁场强度越大,这种变化越明显·与未加磁场的合金相比,经交变磁场处理后的合金,其液相线温度上升了7 5～12 5℃,固相线温度升高了10～20℃·交流磁场作用改变了固液界面前沿液相中的原子团簇向固相跳动时所需克服的势垒,最终导致合金熔点的改变·     

Body size variability and water balance: A comparison between mainland and island populations ofMastomys huberti (Rodentia: Muridae) in Senegal

Generally rodents are found to be larger on islands than on the mainland. However, there are some exceptions to this rule, and the aim of this paper is to examine one of them. On the mainland of Senegal,Mastomys huberti occupies humid habitats. However, it occurs also on dry and sandy islands (Saloum delta), where its representatives are dwarf. Since water availability appeared to be the limiting factor in these islands when compared to the mainland, we studied water turnover characteristics in relation to body size, in mainland and island populations at the end of the dry season, under both field and laboratory conditions. All populations were found to be water balanced in their natural habitats. They presented similar rates of water turnover, even though island animals were subjected to stronger constraints than mainland ones. Laboratory experiments suggested that the physiological plasticity of one of the island populations may be reduced. Island populations have a higher kidney size to body weight ratio than those from the mainland. We propose that smaller size in the islands allows the maintenance of water balance with a smaller amount of water, and that a higher ratio of kidney filtration surface to body size may helpMastomys huberti to survive in dry islands. We discuss the factors responsible for body size variability and variation in water exchange characteristics and conclude that different factors could explain body size variation among island populations, depending on the species considered and the ecological constraints met within the islands.