一种合成单黄酮类化合物的简便方法

黄酮类化合物是植物最普通的成分之一,其合成大多采用查尔酮关环、黄烷酮脱氢、Baker-Venkataraman重排、Allan-Robinson缩合等方法,但这些方法操作较繁。近年来,虽有不少改进,但基本上还是沿用老路线。本文报道合成此类化合物的一种简便方法。以α-卤代邻羟基苯乙酮1(或2)与芳香醛3,     

THE QUANTUM CORRECTIONS ON THE THEORY OF TRANSITION RADIATION

A Scheme of quantum treatment for transition radiation is proposed. The Fresnel coefficients are adopted to describe the stationary states of electromagnetic fields near the interface between two mediums before a canonical field quantization procedure can be performed. Then an usual perturbation approach in field theory leads to the general expressions of radiation intensity in two different polarizations. The second order quantum corrections are ascribed to the existence of electron spin. Some concrete formulas for the cases of electron or monopole acrossing a metal surface are presented as well.

     

Synthesis and Fluorescence Property of A New Subphthalocyanine

Recentlysubphthalocyanines',anewtype0fphthal0cyanine-likecomp0undsandcomp0sedofthreeis0ind0lineunits,werepreparedforthesynthesisofasymmetricalphthal0cyanines.Theirspecialstructure(Schemel)andabundanceofn-electr0nsmakethempossibletobecandidatesforfunctionalmaterials.However,theywereusuallyusedasstartingmaterialsinsyntheticreactions,itsphysicalpr0pertiesrequiredfurtherinvestigations.Schemel.theschematicstructureofsubstitutedsubphthalocyaninan0bor0nInthispapef,(p-phenyl)-tri(2,2-dimethylpropoxy)…     

解非线性互补问题的积分水平集方法

本文考虑有约束的非线性互补问题的全局最优化问题,在文《IntegralGlobalOptimizationMethodforSolutionofNonlinearComplementarityproblem》和《一种修正的求总极值的积分一水平集方法》的基础上,给出了一种修正的求约束总极值的积分一水平集方法,它同样具有修正的求总极值的积分一水平集方法的两个特点：1）每一步需要构造一个新的函数,而且它与原目标函数具有相同的总极值;2）避免了郑权算法在一般情况下,由于水平集不易求得而造成难以求出水平的困难,并证明了算法的收敛性     

兰州放射性核束流线 *

描述了兰州重离子加速器国家实验室最近建成并已投入运行的新装置———兰州放射性核束流线 (RIBLL) .RIBLL是PF型双消色差反对称结构放射性核束分析设备 ,它的立体角接收度≥ 6 .5msr,动量接受度± 5 % ,最大磁刚度4.2Tm ,元素分辨>150 ,质量分辨>300 ,最短分辨时间 <1μs.初级束流的入射角在 0°～ 5°范围可调 .RIBLL已为第一批物理实验提供¹⁷N ,⁸He等多种放射性核束流 .     

有机弱碱体系中氢型硅铝MCM-41介孔分子筛的合成及表征

以有机胺为碱源合成出硅铝介孔分子筛MCM-41,并将合成产物的性能与采用传统方法(以氢氧化钠为碱源)合成的产物进行了对比.所合成产物经焙烧脱除有机表面活性剂后即为氢型.XRD和TEM结果表明,所合成的产物骨架具有很高的有序度.固体核磁共振结果显示,铝原子以四配位的形式存在于样品的原粉中.经过高温焙烧,有少量骨架铝脱出骨架,转变成六配位形式.程序升温吡啶吸附红外光谱证明焙烧后产物具有一定的表面酸性.     

The Simulation of Reflectron Time-of-Flight Mass Spectrometer

Owing to its wide mass range, high sensitivity, fast spectrum registration, and high resolution,the reflectron time-of-flight mass spectrometer is applied to more and more places. The Simulation of the reflectron TOF-MS is vitally necessary and helpful. The software MAPLE and SIMION are employed in our works.     

光度法测定铋(III)与N-苯基硫脲配合反应的热力学参数

The stability constants of complexes of N-phenylthiourea with bismuth (III) in 1M perchloric acid have been studied spectrophotemetrically by the method of corresponding solutions. The enthalpy change ΔH5^0 is obtained from the temperature coefficient data. The Gibbs free energy changes ΔG5^0 and the entropy changes ΔS5^0 are calculated from known formulas respectively. The experimental results are discussed. The successive accumulative stability constants and thermodynamic parameters ΔH5^0, ΔG5^0, ΔS5^0 are listed in Table 6 of the Chinese Text.     

港口柔性评价

港口柔性体现了港口对社会经济环境变化的反应能力和适应能力,科学的港口柔性评价是提高其柔性水平的基础.根据柔性的多维度特征和港口生产服务实际,从战略柔性、结构柔性、管理柔性、生产柔性和可持续柔性五个方面建立了港口柔性评价指标体系;选用模糊ANP方法建立评价模型,即根据各柔性指标之间的依存和反馈关系,用网络分析法(ANP)确定模糊指标权重.模糊ANP方法能够较准确地给出港口柔性的定量评价,为港口采取正确的发展策略、提高柔性水平提供参考.     

Phase Diagram of the Spin-1/2 Heisenberg Alternating Chain in a Magnetic Field *

By using the infinite time-evolving block decimation, we study quantum fidelity and entanglemententropy in the spin-1/2 Heisenberg alternating chain under an external magnetic field .The effects of the magnetic field on the fidelity are investigated, and its relation with the quantum hase transition (QPT) is analyzed. The phase diagram of the model is given accordingly, which supports the Haldane phase, the singlet-dimer phase, the Luttinger liquid phase and the paramagnetic phase. The scaling of entanglement entropy in the gapless Luttinger liquid phase is studied, and the central charge $c=1$ is obtained. We also study the relationship between the quantum coherence, string order parameter and QPTs. Results obtained from these quantum information observations are consistent with the previous reports.