用数字干涉仪测量变形镜影响函数的实验研究

分析了变形反射镜面形影响函数的意义，鉴于自适应光学系统中波前探测大都以测量波前斜率为基础的特点，提出应研究斜率影响函数，并在此基础上构成波前复原矩阵。还介绍了用数字干涉仪测量变形镜影响函数的方法和结果，并对测量结果进行了分析，得到了影响函数的各种参数，例如：交连值，高斯指数，特征宽度等。并将干涉法测量斜率影响函数的结果与实际的哈特探测器的测试结果进行了比较。     

Theoretical study of the vertical electron affinity and ionization potentials of C3

The electron affinity and first three ionization potentials of C₃ are calculated using the multiconfigurational SCF and configuration interaction methods and by Möller-Plesset perturbation theory. Whereas Koopmans' theorem and SCF calculations indicate that the first cation state is ²Π_u, upon inclusion of correlation effects both the ²Σ_u and ²Σ_g cation states are found to lie lower in energy. CI calculations indicate that the ground state (²Π_g) anion is stable by 1.74 eV. Allowing for the error in the calculated electron affinity of the carbon atom, C₃^? is estimated to be stable by 2.0 eV, in excellent agreement with the 2.05 eV value determined from recent photodetachment measurements. No excited anion states are found to be bound at the equilibrium geometry of the neutral molecule.     

Specific heat of YBa2Cu3O7−x from 4.2 to 60 K

The specific heat of superconducting oxide compound, YBa₂Cu₃O_{7 ?x} , is studied using a quasi-adiabatic calorimeter from 4.2 to 60 K. The analysis of the specific heat data below 15 K gives a value of 17 mJ/mole K² for the electronic heat capacity coefficient. The value ofθ _D(0) is determined to be 397±8 K. The variation ofθ _D with temperature was calculated in the temperature range 4.2 to 60 K.     

Electron impact studies on some aryl heteryl ketoximes

The mass spectra of nine aryl heteryl ketoximes indicated that a gaseous phase Beckmann rearrangement occurs to a significant extent, as confirmed by the exact mass measurements of the resulting aroyl cation peaks. Loss of oxygen, hydroxyl radical and migration of the oxime hydrogen to the heterocycle is observed to take place in varying proportions.     

Paradoxes in conditional probability

It is shown that paradoxes arise in conditional probability calculations, due to incomplete specification of the problem at hand. This is illustrated with the Borel and the Kac-Slepian type paradoxes. These are significant in applications including Bayesian inference. Also Rényi's axiomatic setup does not resolve them. An open problem on calculation of conditional probabilities in the continuous case is noted.     

A new synthesis of homoisoflavanones (3-benzyl-4-chromanones)

Two 7-hydroxyhomoisoflavanones ( / ) have been synthesized from corresponding 2'-hydroxydihydrochalcones ( / ) in about 33% overall yields. The stages are : (1) selective protection of C₄'-hydroxyl in ( / ) with EtO.CH₂Cl (1 molar equiv.) In the presence of dry K₂C0₃ and acetone at r.t.; (ii) reaction with one more molar equiv. of EtO.CH₂Cl at 60–70° without Isolating products ( / ) (iii) cyclizatlon of resulting α-hydroxymethyl derivatives ( / ) with 4% aq. aIc. Na₂C0₃ and (iv) deprotection of resulting 7-ethoxymethoxy homoisoflavanones ( / ) with 10% CH₃0H-HC1. The explanations for the formation of ( / ) and ( / ) are given.