机械球磨对石墨结构的影响

对石墨进行了150h机械球磨,发现石墨原有的晶体结构被破坏,引入各种晶格缺陷的同时,生成了巴基洋葱、三脚架形碳纳米结构和纳米弓形等具有高度弯曲石墨面的碳纳米结构材料.还研究了其结构特征,并讨论了其形成机理 关键词：     

癌基因MDM2阻断剂的分子结构的NMR研究

根据P53-MDM2复合物晶体结构,设计合成了非肽类小分子作为MDM2的阻断剂.利用超导核磁共振波谱仪,测定了化合物的¹H谱、¹³C谱、¹H-¹H COSY谱、HMQC和HMBC谱,确定了化合物的结构,归属了化合物的¹H、¹³C化学位移,为筛选抗癌活性化合物提供了理论依据.     

ON THE NEUTRINO MASS,THE ABUNDANCE OF RIGHT-HANDED NEUTRINO AND THE CLOSENESS OF THE UNIVERSE

We point out that although the neutrino mass is finite,the left-handed neutrino density still dominates over the righthanded one in the universe unless there exists one or more elementary fernions (quark or lepton) whose mass is larger than 10⁶ GeV. or M_WR/M_WL≤10². (M_WLand M_WR are the left and right handed intermediate boson respectively.If there exists neutrino the mass of which is about 34 ev. as indicated in some experiments, then one can conclude that the total neutrino mass of the universe s,bvld contribute abput 99%. to the whole masses and lead to the closeness of the universe.This conclusion can be brought to the agreement of all observation datd which have been-obtained so far. A mass limit of all species of neutrinos obtained by reexamining all data is ≤ 200 eV.     

关于动态位错场张量势的规范变换

本文引入并论证了描述动态位错场的张量势(A与B)的规范交换问题,而且证明这种变换可采取这样的形式:B′=B+▽F, A′=A-ρ?/(?t)▽G,x′=x-ρ?/(?t)F,其中x_i=e_iklA_kl。至于F与G,则为带有很大任意性的时空坐标的矢量函数,但它们要满足以下关系式:F=▽×G,▽²F-1/G_t²-(?²/?t²)F=0.进 关键词：     

热阴极电离真空计的线性理论

从繁流放电理论可直接导出热阴极电离真空计的特性方程,证明通常的概念即在热计的电子流i_e一定时其离子流i₊与压强P成正比的关系,只在离子流甚小于电子流时才能成立。在被测气体的压强较高时,离子流和压强之间呈现下列指数关系: i₊/i_e=1-e^{(-(K₁P-K₂P2))}(K₁及K₂为常数),且随着压强的增长而逐步趋于饱和。进一步的推导则得出,当容许测量误差为1％时,热计的线性上限(临界压强)为P_c=0.22/Г,此处Г为热计的灵敏度。这种理论可以容易地解释近年来一些实验工作者例如Nottingham,Schultz,Goto,Hinzpeter等的实验结果。此外我们还使用了特殊设计的“封闭式”电离计作实验,得到的结果和理论预计十分符合。这种电离计本身则可用作10^-7～0.6托的宽程量具。 关键词：     

溴代还原青蒿晶体结构研究

溴代还原青蒿(C₁₇H₂₇O₅Br),晶体属单斜晶系,空间群P2₁。晶胞中含两个分子。晶胞参数:α=10.34?,b=9.160?,c=9.353?;β=90°,z=2。衍射数据由Philips PW-1100四圆衍射仪测定。用Patterson法求解。晶胞中两个重原子溴呈中心对称配置,故生双解。分别用立体化学知识判别和用直接法均得到同一套单解。分子的绝对构型是用反常散射法确定的。用全矩阵最小二乘法对原子坐标参数、比例 关键词：     

近邻原子的空间排列对非晶态铁磁体自旋波谱的影响

关键词：     

ON THE APPLICATION OF THE HILCER PRISM INTERFEROMETER TO THE RESOLUTION OF SPECTRAL LINES

An interference pattern of two systems of fringes has been obtained by vising two radiations in a Hilger prism interferometer A system of white bands with equal spacing which are always parallel to the refracting, edge of the prisin is the result of the intersection of the two systems of fringes. The white bauds travel as one of the reflecting mirror in the interferometer makes a parallel displacement. Let d be the displacement of mirror when the white bauds travel one spacing, we have 1/λ₂-1/λ₁=1/2d. Two yellow doublets in sodium and mercury lamps were used. The values found for 1/λ₂-1/λ₁ were 17.22cm^-1 and 63.29cm^-1 respectively. A comparison of this method with the visibility corve by Michelson interfero-ineter has been discussed.     

等能谷间杂质散射对无序层状系统电导率的影响

本文研究了等能谷间杂质散射对无序层状系统电导率的影响,求得了依赖于平面间耦合t的系统的有效维数的电导率修正。并且发现在计及等能谷间杂质散射时,电导率修正比只考虑谷内杂质散射时小一半,我们研究了层伏系统从二维过渡到三维的跨越维数效应,发现跨越行为依赖于谷间散射时间τ′,当t<1/τ(τ₀/τ′)^1/2时,系统具有二维行为,反之系统具有三维特征。 关键词：     

溅射气压对X射线多层膜反射率的影响

本文在不同的溅射气压的情况下制备了具有相同结构参量的Mo/Si多层膜,测出了其对应的小角度X衍射曲线,在北京同步辐射实验室测量了多层膜的软X射线反射率.小角X射线衍射谱表明:随着溅射气压升高,多层膜的小角X射线衍射曲线的高次峰的峰高急剧变小,半峰宽变大.反射率测量结果也表明:多层膜的X射线反射率随溅射气压的升高而急剧降低.