当方差未知时选取有最大均值总体的两阶段抽样方案

考虑ｋ个有连续分布Ｆｉ＝Ｆ（ｘ－μｉ／σ）的总体，ｉ＝１，．．．，ｋ。其中μｉ和σ均未知，我们通过两阶段抽取样本以得到最大均值的那个总体，第一步根据抽样删去一部分看来不可能的总体，第二步再从余下总体中抽样，取含样本均值最大的那个总体为所需总体，我们用渐过分布方法得到了在所定规则下能选到正确总体的概率下界。特别对Ｌｏｇｉｓｔｉｃ总体计算了有关数值以及关于一次抽样的相对效。     

MULTIDENTATE LIGAND EXCHANGE KINETICS:REACTIONS OF AMINOCARBOXYLATO-FERRATE(Ⅲ) COMPLEXES WITH 4-(2-PYRIDYLAZO) RESORCINOL

The kinetics and mechanism of ligand substitution reactions of nitnlotriacetatoiron(Ⅲ),(Fe(NTA)],and N-(2-hydroxycthyl)-ethylencdiaminetriacetatoiron(Ⅲ),[Fe(HEDTA)],complexes with 4-(2-pyridylazo) resorcinol (Par) has been investigated at pH=9.0±0.02,I=0.1mol·l^-1 (NaClO₄,and temp.=25±0.1℃ and 30±0.1℃ respectively. The reaction has been studied spectrophotometrically at 496 nm. (λmax of Fe(Par)₂. In both reactions the final product was [Fe(Par)₂]^-. The values of second order rate constants for NTA and HEDTA exchange reactions are (10.0±0.8)×10¹¹·mol^-1·s^-1 and (2.7±0.1)×10^-1·mol^-1·s_-1 respectively. The reactions of NTA and HEDTA exchange were studied in the pH range 6-9.5 and 7-10.85 respectively. The rate of reacton of [Fe(NTA)] with HPar^- first increases with pH and then levels off. However,in the case of [Fe(HEDTA)] reaction,the rate increases monotonically with increase of pH in the specified range.     

A Method for Solving Moving Boundary Problems in Heat Flow using Cubic Splines or Polynomials

A new approach to a heat-flow problem involving a moving boundarymakes use of a grid system which moves with the boundary. Twovariations of the method are described. In the first, necessaryinterpolations are performed by using cubic splines; in thesecond, cubic polynomials are employed. The method smooths outirregularities in the motion of the boundary which were evidentin previous calculations based on a fixed grid system.     

Dynamical after-effects of nuclear decay in Mössbauer resonance

A general expression has been derived for the spectral distribution of Mössbauer radiation in presence of both lattice dynamical and electronic aftereffects of nuclear decay. The expression has been used to calculate Mössbauer spectrum in a possible experimental situation where the decaying atomic state results in a change in hyperfine interactions as well as a change in the binding of the Mössbauer atom in the lattice.     

Spectroscopy and laser characterization of synthesized supramolecular host cucurbit[7]uril using aqueous Rhodamine B dye

Recent demonstration in augmenting the efficiency of aqueous Rhodamine dye lasers using cucurbit[7]uril (CB[7]), a deaggregating and photostabilizing host, has drawn interest in the synthesis and characterization of spectroscopic grade CB[7] in larger quantities. Synthesis of cucurbituril group of macrocycles always leads to the formation of various homologues of CB[n]s (n=5–7) with CB[7] as the minor product. The literature procedure has been optimized to get pure CB[7] in 12–14% yield by fractional crystallization and the purity was checked by NMR, MS and spectrophotometric titration. Laser performances of the synthesized and commercial CB[7] sample as an additive were evaluated using Nd-YAG (532 nm) pumped Rhodamine B aqueous dye lasers and comparable results were obtained.     

Optical probing of Eu ions confined in an RF trap

The Eu ions confined in an RF quadrupole trap, has been optically detected. Using a tunable dye laser which is pumped by a Nd-YAG pulsed laser system, the resonance ⁹S₄^9S_4–6p _3/2, J = 5 transition of the Eu ions have been excited and the resulting fluorescence to the metastable ⁹D_4-6^9D_{4-6} state has been detected. In preparation to determine the ground-state hyperfine splitting of the odd isotopes we found the optimum trapping operating point. We have also observed a number of instabilities inside the region of the stability for an ideal trap. These non-linear resonances arise from higher-order contributions to the ideal quadrupole potential.     

ChemInform Abstract: Investigation of the Electronic Structure of the New Quaternary Hydride PdSr2LiH5.

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