不饱和类卡宾H_2C＝CNaX(X=F,Cl,Br)的密度泛函理论研究

采用密度泛函理论方法,在B3LYP/6-311+G(d,p)水平上研究了不饱和类卡宾H2C=CNa X(X=F,Cl,Br)的结构.结果表明,不饱和类卡宾H2C=CNa X(X=F,Cl,Br)各有2种平衡构型,其中具有三元环结构的构型能量低,是其存在的主要构型.预言了最稳定构型的振动频率和红外强度.计算得到了最稳定构型分子内氢迁移反应的过渡态.讨论了卤原子对不饱和类卡宾H2C=CNa X的影响.     

我国新生牛血清~(60)Coγ-射线照射技术的研究现状

新生牛血清是医药生物技术产品重要的原辅材料,其质量是生物制品质量保证的重要环节,国内的新生牛血清用60Coγ-射线照射已有多年,但还没有形成统一的操作规范和技术标准.文章对我国新生牛血清60 Coγ-射线照射的现况进行了分析总结,同时呼吁有关部门加强监督管理和技术指导,使60Coγ-射线照射技术在新生牛血清中得到更规范的应用.     

La$_{{1-x}}$Sr$_{x}$TiO$_{3}$ 薄膜的高通量 X 射线衍射

高通量材料合成方法和高通量材料表征手段区别于传统低效率的 "试错法"材料发展方法, 极大地加速了材料科学的变革和发展. 通过设计程序进行了高通量 X 射线衍射实验, 在保证数据分辨率条件下, 高效地表征了 La$_{1-x}$Sr$_{x}$TiO$_{3}$ 薄膜上多个数据位点的晶体结构, 验证了其成分的连续变化性质, 为后续开展更多类型的高通量 X 射线衍射实验提供了指导.     

X射线反射强度与温度的关系

由实验测出铝的X射线反射谱线的强度,得到其反射强度随温度变化的曲线,并从理论上对实验结果作了分析,得到了X射线反射强度随温度的增高而减弱,而谱线的锐度却不随温度升高而受到损失的结论.     

Study of an athermal infrared dual band optical system design containing harmonic diffractive element

A harmonic diffractive element (HDE) is first successfully introduced to the athermal system of infrared dual band in this paper. In this system, there are only three lens and two materials, silicon and germanium. When the temperature ranges from -70℃ to 100℃ in the dual band,it can simultaneously accomplish the rectification of the longitudinal aberration in the big field of view, as well as the wave front aberration less than 1/4 wavelength. Modulation transfer function of dual band approaches or attains the diffraction limit. The calculation results show that the spectral properties of the HDE are between refractive and diffractive elements, so we can design a simple dual-band and athermal optical system by selecting the thickness and central wavelength of the HDE exactly. Compared with a conventional refractive optical system, this system not only reduces the demand for high technical levels, but also has a compact structure, few elements, a high transmittance better aberrations performances and athermal character. At the same time, the use of the HDE also offers a new element for the infrared optics design.     

“黎东防护”：扬鞭催马跨征程

上海黎东射线防护科技发展有限公司是以射线防护技术开发、技术转让、技术咨询、技术服务，射线防护材料生产、销售、射线防护工程承包等为主的一体化工业公司。     

印度天文学介绍

印度是一个历史悠久的文明古国.它对天文学进行研究的历史一直可以追朔到公元前,近些年来,由于国家经济的发展和科技的进步,使印度天文学学术研究机构和装备取得了很大的提高和完善.本文对印度天文学方面的发展历史和近况作了较为详细的介绍,以期引起读者对它的关注.     

Studies on the Crystallization Properties and Morphology Structure of the Cationic Dyeable Polypropylene Fibers

The crystallization properties and morphology structure of the cationic dyeable polypropylene fibers which were produced by the blending spinning method were studied by making use of X-ray and scanning electron microscopy (SEM). It comes to the conclusions that the larger the crystallite size in the fibers is , the better the dycable properties of the fibers are and there is a little compatibility between the dyeable agent and polypropylene resin. And the dye-uptake of the fibers may be up to 90% because the dyeable agent can uniformly be scattered in polypropylene.