Microstructure change in deuterium implanted CLAM steel induced by electron irradiation

As Reduced Activation Ferritic/Martensitic (RAFM) steel is considered the primary candidate for use as a structural material in fusion power reactors,many countries are developing different kinds of RAFM.China is developing new CLAM (China Low Activation Martensitic) steel.The study investigates microstructural changes in CLAM steel implanted with deuterium ions induced by 1250 keV electron irradiation from R.T.to 873 K,and observes both the growth and shrinkage of the defect clusters produced by deuterium ...     

NQR Study of Phase Transition and Cationic Motion in 4-NH2C5H4NHBiBr4·H2O

Four ⁸¹Br NQR lines in 4-NH₂C₅H₄NHBiBr₄·H₂O were observed in the temperature range between 77 and ca. 380 K; with increasing temperatures the respective sets of higher and lower two resonance lines coalesced into single lines discontinuously at 274 K, showing the occurrence of a first-order type phase transition of this crystal. The transition was confirmed with heat anomaly on a DTA curve. Each higher and lower line of high-temperature phase is assignable to the terminal Br atoms and the bridging ones of one-dimensional poly anions (BiBr₄ ⁻) _n in the crystal structure (C2/c), which was investigated by a X-ray structure analysis at room temperature. The 1/T ₁ temperature dependence of ⁸¹Br NQR follows the usual T ² law in the temperature range between 77 and ca. 140 K, being explained by fluctuation of the EFG at Br nucleus due to lattice vibrations. The T ₁ vs. 1/T curve in the temperature range between about 160 and 190 K was describable by the exponential curves, allowing us the estimation of activation energies. These exponential behaviors of T ₁ of ⁸¹Br NQR are attributable to the fluctuations caused by the thermal motion of 4-NH₂C₅H₄H⁺ ions. Echo signals of the ⁸¹Br NQR could not be detected above 190 K owing to poor S/N with very short T ₂.     

Fast and Accurate Phase Retardation Measurement of 0° Twisted Nematic Liquid Crystal Panels Based on the Principle of Homodyne Receiving

We describe herein a method to measure quickly (in less than 2 min) and accurately the phase retardation between the extraordinary and ordinary axis of homogeneous or 0° twisted nematic liquid crystal panels. Owing to the homodyne detection scheme, the setup allows us to probe liquid crystal (LC) panels with an optical power down to a fraction of 1 nW and, hence makes it possible to focus the light beam to a spot of only a few wavelengths in diameter without heating or inducing observable variations in the liquid crystal. The dependence of the phase retardation on the LC driver frequency and the temperature are presented and compared with the theoretical prediction.     

木根黄芩中-新黄酮的光谱特征

从木根黄芩(Scutellaria planipes Nakai et Kitag.)中分离得到一新黄酮类化合物. 该化合物被鉴定为5,7,3′,6′-tetrahydroxy-6,8,2′-trimethoxyflavone. 它有很强的抑制5-酯氧合酶活性. 由于该化合物的A环全部被取代，因此，应用一般的光谱技术很难准确归属各碳的化学位移. 我们应用¹³C-¹³C相关谱和酰化位移方法，明确归属了各碳的信号，并订正了文献中对部分信号的错误归属.     

用正电子湮没研究NiAl中的晶体缺陷

用正电子湮没技术研究了金属间化合物NiAl的结构缺陷、淬火缺陷和电子辐照缺陷,观察了淬火缺陷和辐照缺陷的回复行为。发现在280℃左右和500℃左右有两个明显的回复阶段。实验结果分析表明:低温回复是由于空位对的退火,而高温回复是由于单空位的退火而引起,并且NiAl中空位和晶格间隙处的导电电子密度较接近,但空位处的导电电子的动量比晶格间隙处的低。 关键词：