Cu50Ti50非晶态合金的中子辐照效应

本文叙述了用X射线衍射和differential scanning calorimetry(缩写为DSC)测量两种方法对Cu₅₀Ti₅₀非晶态合金进行的快中子辐照效应研究。辐照不仅改变了该合金晶化峰的温度,而且还改变了晶化峰的形貌。在X射线衍射研究中还观察到辐照对结构所产生的影响恰与低温退火的影响相反。在这两种实验结果的基础上,讨论了Cu₅₀Ti₅₀非晶态合金的快中子辐照与原子短程结构变化的关系。 关键词：     

光纤通信讲座 光波复用光纤通信

目前进入实用化阶段的光纤通信系统只有IM/DD(光强调制/直接探测)方式一种.经过多年的努力,这种方式达到的最高信息速率仅为8×109b/s(比特/秒).尽管光纤孤子通信[1]和光纤相干通信[2]有可能把这一指标提高几个量级,但是,这和光纤通信理论上的信息容量仍相差很远,况且这些新的通信方式目前仅仅处于研究阶段,距离实用化还有一段较长的时间.因此,为了充分挖掘和发挥光纤传输信息的潜力,近年来又提出并积极开展复用光纤传输技术的研究. 复用技术是一种能够充分利用传输线的信道容量的通信技术.它是先把来自若干信息源的消息进行合并,然后将这…     

弹性水锤对水电站调节稳定性的影响

过去文献当考虑弹性水锤对调节稳定性影响时,仅针对某单一个工作点应用频率反应判定运转是否稳定。本文应用水锤连续和动量方程导得通用的临界稳定曲线式,由此曲线在同一图上给出任何工作点是否稳定的判定。对三个无调压井的水电站和二个有调压井的水电站(其中一个是有支洞的),进行了计算,得出了定量的结果。若就定性的而言,考虑弹性影响的稳定域总比不考虑的为小;调压井有使弹性影响稍减小的趋势。     

石墨炉原子吸收光谱法测定奶牛血清中硒

本文采用石墨炉原子吸收技术加入基体改进剂直接测定奶牛血清中的痕量元素硒。实验发现使用0.1%Ni(NO3)2作为基体改进剂，可使样品灰化温度提高到1000℃，实际使用灰化温度为600℃经氕灯校正背景，直接测定奶牛血清中的硒含量方法简便省时，回收率在104%-93.3%之间，相对标准偏差为4.9%。     

ORIGIN OF MONOAMINERGIC INNERVATION OF THE NUCLEUS RAPHE MAGNUS——A COMBINED MONOAMINE HISTOCHEMISTRY AND FLUORESCENT RETROGRADE TRACING STUDY IN THE RAT

By the use of the fluorescent retrograde tracer, Fast Blue (FB), in combination with monoamine fluorescence histochemistry, the origin of monoaminergic input to the region of the nucleus raphe magnus (NRM) was investigated in the rat. After mieroinjection of FB into the NRM, a great number of FB-laboled NA-containing cells were found in the region of the nucleus reticularis lateralis (corresponding to A1 NA areas), the reticular formation just dorsolateral to the nucleus olivaris inferior (corresponding to the A3 NA area), the ventral part of the locus coeruleus (A6 NA area), and the lateral parts of the nucleus raphe dorsalis (B7 area). In the other NA cell groups of the brain stem, FB-labeled cells could not be observed. Serotoninergic input originating from nucleus raphe obscurus (B2), nucleus raphe pallidus (B1) and nucleus raphe pontis (BS-B6) to the NRM was also observed. A large number of cells containing serotonin (5-HT) in the B2 and B6 areas were labeled by FB, while only a few FB-labeled 5-HT     

Yb~(3+)-doped double-clad fiber laser with all fiber cavity

A novel all fiber cavity Yb~(3+)-doped double-clad fiber laser (DCFL) based on two double-clad fiber (DCF) Bragg grating is presented. The fiber Bragg gratings (FBGs) as the input and output mirrors have been formed in Yb~(3+)-doped DCF with the phase-mask method, and their reflectivities are 99% and 22%, respectively. When the input pump power is 417 mW, the maximum output power is 144 mW with linewidth <0.1 nm at the wavelength of 1.057 μm, over 40-dB signal-to-noise ratio (SNR), and 50.8% slope efficiency.     

手征σ模型中σ介子的质量与核物质结合能曲线关系的研究

文中研究了手征σ模型下σ介子的质量m_σ与核物质结合能曲线的关系,主要的目的是研究在单圈图近似下所谓的“快子极点”问题,即σ或π介子质量的平方变为负数,这将导致能量密度为虚数.把m_σ看成自由参数并通过拟合核物质的饱和性质而确定,结果表明,在单圈图真空起伏近似下,并选重整化点在质量壳上,当m_σ=307.5MeV而且核密度小于4.43倍正常饱和密度时,“快子极点”没有出现,因此首先得到了核物质结合能曲线以及计算了不可压缩系数K(≌175.7MeV).     

DNTF的合成与表征

3，4-二（硝基呋咱基）氧化呋咱（DNTF）是一新型高能量密度化合物，其感度较HMX的低，能量较HMX的高，与CL-20的相当。文中对DNTF及其中间体3-氨基-4-酰胺肟基呋咱（AAOF），3-氨基-4-酰氯肟基呋咱（ACOF），3，4-二（氨基呋咱基）氧化呋咱（DATF）及其异构体3，6-二（3＇-氨基呋咱基-4-基）-1，4-二氧杂-2，5-二氮杂环己-2，5-二烯（BADDD）的合成，表征和主要的物化和炸药性能进行了报道。     

Two-electron and one-photon transitions in highly charged nickel-like ions

This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon (TEOP) transition from the $(3{\rm s}^{-1}_{1/2}4{\rm d}_{j})_{J=1,2}$ to $(3{\rm p}^{-1}_{3/2}4{\rm s}_{1/2})_{J=1}$ and the $(3{\rm p}^{-1}_{1/2}4{\rm s}_{1/2})_{J=1}$ to $(3{\rm d}^{-1}_{j}4{\rm d}_{j'})_{J=1,2}$ for highly charged Ni-like ions with atomic number $Z$ in the range $47\leq Z\leq92$. In the calculations, the multi-configuration Dirac--Fock method and corresponding program packages GRASP92 and REOS99 were used, and the relativistic effects, correlation effects and relaxation effects were considered systematically. It is found that the TEOP transitions are very sensitive to the correlation of electrons, and the probabilities will be enhanced sharply in some special $Z$ regions along the isoelectronic sequence. The present TEOP transition wavelengths are compared with the available data from some previous publications, good agreement is obtained.     

级联双折射光纤环镜滤波特性的分析

从理论上研究了级联双折射光纤环镜滤波器的滤波特性，给出加隔离器与不加隔离器两种不同结构的串联双环镜滤波器透射光强的表达式，并对于两个环镜取不同的周期比时的滤波特性进行了数值模拟和分析.得出串联环镜滤波效果与级联顺序无关，光隔离器对滤波效果不会产生影响，只是增加了插入损耗.通过级联和改变两个环镜的双折射光纤长度比，可以获得不同的滤波效果.最后给出了多个环镜直接级联后透射光强的通项表达式，通过对通项式的理论分析可以设计不同的滤波器.